Topic: Let's build a pre-amp!

[peterbilt]

Seriously! With the vast knowledge contained in the craniums of all the folks here, why not?
Several folks have dissected their's and checked out the particulars of op amps and capacitors and whatnot. Is it really difficult to get ahold of these particular pieces?
There are schematics for battery boxes and such, why not an AC or DC powered device?
Have any of you built any of the pre amp kits that are available?

I dunno, I'm just rambling....

[Church-Audio]

To late I already did

Chris Church

I want to build a neve based preamp that will run on batteries next. 60to70db of gain no noise great specs transfomer inputs and outs with a basic Neve design. thats my personal goal let me know if you need some help with your design.

Seriously! With the vast knowledge contained in the craniums of all the folks here, why not?
Several folks have dissected their's and checked out the particulars of op amps and capacitors and whatnot. Is it really difficult to get ahold of these particular pieces?
There are schematics for battery boxes and such, why not an AC or DC powered device?
Have any of you built any of the pre amp kits that are available?

I dunno, I'm just rambling....

[udovdh]

Seriously! With the vast knowledge contained in the craniums of all the folks here, why not?
Several folks have dissected their's and checked out the particulars of op amps and capacitors and whatnot. Is it really difficult to get ahold of these particular pieces?
There are schematics for battery boxes and such, why not an AC or DC powered device?
Have any of you built any of the pre amp kits that are available?

I dunno, I'm just rambling....

Sounds interesting.
You'll find out everyone wants something different.
E.g. I just need a simple buffer, maybe slight gain (6-10 dB?). Single 9V battery, clean 16-bit audio...
Others want balanced connections, better specs, etc.

[RebelRebel]

Too bad there are 3 million neve clones out there already.  The neve portico runs on batteries.

To late I already did

Chris Church

I want to build a neve based preamp that will run on batteries next. 60to70db of gain no noise great specs transfomer inputs and outs with a basic Neve design. thats my personal goal let me know if you need some help with your design.

Seriously! With the vast knowledge contained in the craniums of all the folks here, why not?
Several folks have dissected their's and checked out the particulars of op amps and capacitors and whatnot. Is it really difficult to get ahold of these particular pieces?
There are schematics for battery boxes and such, why not an AC or DC powered device?
Have any of you built any of the pre amp kits that are available?

I dunno, I'm just rambling....

[Church-Audio]

I know lots of Neve clones. Maybe I should just try to build a good Balanaced mic pre with good meters? hummm something that runs on batteries and is very small (stereo) how much gain should it have? for this type of work 40-50db with a really good pad for close micing?

Too bad there are 3 million neve clones out there already.  The neve portico runs on batteries.

To late I already did

Chris Church

I want to build a neve based preamp that will run on batteries next. 60to70db of gain no noise great specs transfomer inputs and outs with a basic Neve design. thats my personal goal let me know if you need some help with your design.

Seriously! With the vast knowledge contained in the craniums of all the folks here, why not?
Several folks have dissected their's and checked out the particulars of op amps and capacitors and whatnot. Is it really difficult to get ahold of these particular pieces?
There are schematics for battery boxes and such, why not an AC or DC powered device?
Have any of you built any of the pre amp kits that are available?

I dunno, I'm just rambling....

[RebelRebel]

Something to replace the m148 im sure would please a lot of tapers..

I know lots of Neve clones. Maybe I should just try to build a good Balanaced mic pre with good meters? hummm something that runs on batteries and is very small (stereo) how much gain should it have? for this type of work 40-50db with a really good pad for close micing?

Too bad there are 3 million neve clones out there already.  The neve portico runs on batteries.

To late I already did

Chris Church

I want to build a neve based preamp that will run on batteries next. 60to70db of gain no noise great specs transfomer inputs and outs with a basic Neve design. thats my personal goal let me know if you need some help with your design.

Seriously! With the vast knowledge contained in the craniums of all the folks here, why not?
Several folks have dissected their's and checked out the particulars of op amps and capacitors and whatnot. Is it really difficult to get ahold of these particular pieces?
There are schematics for battery boxes and such, why not an AC or DC powered device?
Have any of you built any of the pre amp kits that are available?

I dunno, I'm just rambling....

[Javier Cinakowski]

My Dream Preamp:

- 48/9v switchable phantom power
- 0-40dB gain range (with knob adjustor)
- 3 LED level lights
- 20bit ADC
- xlr inputs
- 1/8" input
- RCA output (analog)
- 1/8" output (analog and optical)
- tos-link digital output
- runs on 9v or 12v standard batteries or external power supply

oops, i am describing the core2496.  

If someone makes a better preamp, I will buy it.

[RebelRebel]

transformer balanced, variable gain...high gain for ribbons, switchable phantom power

[Church-Audio]

I don't want to get into digital persoanally because it limits the life of the productm, a good preamp without digital is a good preamp and will last and be usefull for many years we all think 192 k and 98k are the best right now and they are, but wait 10 years and see where sample rates are

My Dream Preamp:

- 48/9v switchable phantom power
- 0-40dB gain range (with knob adjustor)
- 3 LED level lights
- 20bit ADC
- xlr inputs
- 1/8" input
- RCA output (analog)
- 1/8" output (analog and optical)
- tos-link digital output
- runs on 9v or 12v standard batteries or external power supply

oops, i am describing the core2496.  

If someone makes a better preamp, I will buy it.

[hyperplane]

I don't want to get into digital persoanally because it limits the life of the productm, a good preamp without digital is a good preamp and will last and be usefull for many years we all think 192 k and 98k are the best right now and they are, but wait 10 years and see where sample rates are

I see what you mean, Chris, and I agree to an extent. However, look at 24-bit even... it's "taken off" as far as the field taping folks here. But you don't see many portable 24-bit players available as a standard audio player in an automobile, for example. So, in a lot of ways, even a good 16-bit ADC is still "ample" for plenty of people who don't want to bother with resampling their masters so they can listen to them in the car or on their ipod. Point being, it will take *a while* I suspect for 192 kHz to become norm such that it's available in a host of portable players.

[Swanny]

I totally agree a good pre will always be good. An AD is only as good as the current standard. I would be interested in a preamp containing:

transformer based (like my 148)
xlr I/O
48v only
2 gain settings one for hotter mics and another for weaker ones
external power by a walmart 9v...
I don't care much for lights, as long is it won't destort ever
small as possible

[poorlyconditioned]

I know lots of Neve clones. Maybe I should just try to build a good Balanaced mic pre with good meters? hummm something that runs on batteries and is very small (stereo) how much gain should it have? for this type of work 40-50db with a really good pad for close micing?

Too bad there are 3 million neve clones out there already.  The neve portico runs on batteries.

To late I already did

Chris Church

I want to build a neve based preamp that will run on batteries next. 60to70db of gain no noise great specs transfomer inputs and outs with a basic Neve design. thats my personal goal let me know if you need some help with your design.

Seriously! With the vast knowledge contained in the craniums of all the folks here, why not?
Several folks have dissected their's and checked out the particulars of op amps and capacitors and whatnot. Is it really difficult to get ahold of these particular pieces?
There are schematics for battery boxes and such, why not an AC or DC powered device?
Have any of you built any of the pre amp kits that are available?

I dunno, I'm just rambling....

I think something to aim for might be a very simple SSM201x/INA103/217 based design.  No phantom power either, just a good solid design that will run on a single 9V battery.  Many of us use electret type mics and don't need phantom power anyway.

By the way, this is the type used in the V2, and also the DMIC-20.  I haven't seen the V2, it probably has a lot of extra stuff (eg., extra opamps for input compensation/balancing/servo or whatever), but the DMIC-20 has a very simple design: a single pair of SSM2019 chips then MC33079 buffers to provide a balanced input to the ADC.

I've got an old PS2 that is broken.  I'm tempted to use this nice case (with cool battery holder and XLR connectors) and build a preamp into it.  The main requirement is to get a nice balanced (eg., +/-12V, 10mA) power supply from a single 9V battery.  I'm looking at doing that with "charge pump" type chips like LT1054 or similar Maxim parts.

If anyone wants to discuss this, follow up here or by PM.

  Richard

[Church-Audio]

Would you not want a rail splitter like the TLE2426. Also what about insted of using ic's why not use fet's? much less current draw and more bang for the buck what do you think? I think phantom is a must how about building a single preamp that can do your basic two wire or three wire or balanced XLR would be very good. But it would have to be small only because if you were going to run two or three wire you would want a stealth preamp right? I think this is totally something that can be done.

Chris Church

I know lots of Neve clones. Maybe I should just try to build a good Balanaced mic pre with good meters? hummm something that runs on batteries and is very small (stereo) how much gain should it have? for this type of work 40-50db with a really good pad for close micing?

Too bad there are 3 million neve clones out there already.  The neve portico runs on batteries.

To late I already did

Chris Church

I want to build a neve based preamp that will run on batteries next. 60to70db of gain no noise great specs transfomer inputs and outs with a basic Neve design. thats my personal goal let me know if you need some help with your design.

Seriously! With the vast knowledge contained in the craniums of all the folks here, why not?
Several folks have dissected their's and checked out the particulars of op amps and capacitors and whatnot. Is it really difficult to get ahold of these particular pieces?
There are schematics for battery boxes and such, why not an AC or DC powered device?
Have any of you built any of the pre amp kits that are available?

I dunno, I'm just rambling....

I think something to aim for might be a very simple SSM201x/INA103/217 based design.  No phantom power either, just a good solid design that will run on a single 9V battery.  Many of us use electret type mics and don't need phantom power anyway.

By the way, this is the type used in the V2, and also the DMIC-20.  I haven't seen the V2, it probably has a lot of extra stuff (eg., extra opamps for input compensation/balancing/servo or whatever), but the DMIC-20 has a very simple design: a single pair of SSM2019 chips then MC33079 buffers to provide a balanced input to the ADC.

I've got an old PS2 that is broken.  I'm tempted to use this nice case (with cool battery holder and XLR connectors) and build a preamp into it.  The main requirement is to get a nice balanced (eg., +/-12V, 10mA) power supply from a single 9V battery.  I'm looking at doing that with "charge pump" type chips like LT1054 or similar Maxim parts.

If anyone wants to discuss this, follow up here or by PM.

  Richard

[lordbelial]

My dream preamp would be.

- Mini XLR input (if 3-wire bbox is included in the preamp) or 1/8'' input (no bbox function)
- Optical output (ADC stage) or minijack output (no ADC)
- 0-30 db variable gain (knob control)
- IC based (burr brown as Richard and Chris "church audio" said before)
- Small (for stealthing purposes)
- Should have to run with single 9 Volt battery

[(((KB)))]

Nick Z's "V2 Killer" project will be finished soon. I believe I'm doing the field tests to it when it's done. I saw the prototype board to it. Basically, it has the IC's etc. of a  V2 without all the bells & wistles. 6v DC, 2 ch, xlr in-out, 48v phantom, clip LED's. Not sure what else he's planning to add, more ch's, ch pans, headphone/ AUX jacks, an ADC? I have the board pic, but I'd have to ask if I could post it first. If anyone is interested, let me know.

-K

[poorlyconditioned]

Nick Z's "V2 Killer" project will be finished soon. I believe I'm doing the field tests to it when it's done. I saw the prototype board to it. Basically, it has the IC's etc. of a  V2 without all the bells & wistles. 6v DC, 2 ch, xlr in-out, 48v phantom, clip LED's. Not sure what else he's planning to add, more ch's, ch pans, headphone/ AUX jacks, an ADC? I have the board pic, but I'd have to ask if I could post it first. If anyone is interested, let me know.

-K

Of course.  Please post any info.  Sounds great!

  Richard

[Krispy D]

Nick Z's "V2 Killer" project will be finished soon. I believe I'm doing the field tests to it when it's done. I saw the prototype board to it. Basically, it has the IC's etc. of a  V2 without all the bells & wistles. 6v DC, 2 ch, xlr in-out, 48v phantom, clip LED's. Not sure what else he's planning to add, more ch's, ch pans, headphone/ AUX jacks, an ADC? I have the board pic, but I'd have to ask if I could post it first. If anyone is interested, let me know.

-K

ding ding ding!

post away!

[tubehead]

Hey y'all this is my micpre that i've been working on, still in R+D tho at this point...in the pic the preamp PCB is stuffed and working, the smaller board is the AC power supply on a proto-board (in debug) and not in the picture are the metering circuit and phantom power supply which I have designs for on paper but no physical prototypes yet...I had planned it to be an AC powered studio device initially with a portable version to be developed later - the phantom supply is way easier to design using AC and a step-up transformer so I figured I'd go for that first...but due to time constraints both have been put on the back burner...on top of that I'm starting grad school in the fall so my free time is pretty skinny, but if there is enough interest I can pick up development again...the design is a one-gain stage minimalistic design using high quality parts - film caps, the same instrumentaion amplifier (burr brown INA103) as the V2, stepped gain settings etc. It sounds really clean and open, even with the bench supply I was using...bandwidth in the 100kHz+ range, balanced in, single ended output that can be used balanced because of a nifty impedance mirror circuit I found on shure's (or jensen's?) website...I had a batch of 10 boards made so i have 8 bare boards left...if you wanted to find a way to power the pre board and work out the phantom, metering and enclosure yourself I could be talked into getting rid of a few maybe...I'm planning on doing a solid brass plate enclosure so it'll be heavy-duty once I get the other circuits done and get to the box level design...I was thinking about using mini-XLRs but passed on the idea because everybody would have to get new cables made...although it was encouraging that somebody made a req for them Other than that, some of you migh know that i am also the 'engineering' half of custom connects, making the VX pocket lo-profile coax I/O, headphone cables, so I've been lurking on here for a while....old habits die hard, i've been lurking in newsgroups since the 80s feel free to drop me a line via email: nmz77@yahoo.com 

l8r...Nick


hmmm, no pic in the preview?! hopefully it will be attached to the post....

[RebelRebel]

heres the green mic pre..maybe itll give some ideas
http://www.diyfactory.com/projects/green/green.htm
http://1176neve.tripod.com/id10.html

and some schematics
http://www.gyraf.dk/schematics/schematics.html
http://www.one-electron.com/FC_ProAudio.html

[(((KB)))]

Hey y'all this is my micpre that i've been working on, still in R+D tho at this point...in the pic the preamp PCB is stuffed and working, the smaller board is the AC power supply on a proto-board (in debug) and not in the picture are the metering circuit and phantom power supply which I have designs for on paper but no physical prototypes yet...I had planned it to be an AC powered studio device initially with a portable version to be developed later - the phantom supply is way easier to design using AC and a step-up transformer so I figured I'd go for that first...but due to time constraints both have been put on the back burner...on top of that I'm starting grad school in the fall so my free time is pretty skinny, but if there is enough interest I can pick up development again...the design is a one-gain stage minimalistic design using high quality parts - film caps, the same instrumentaion amplifier (burr brown INA103) as the V2, stepped gain settings etc. It sounds really clean and open, even with the bench supply I was using...bandwidth in the 100kHz+ range, balanced in, single ended output that can be used balanced because of a nifty impedance mirror circuit I found on shure's (or jensen's?) website...I had a batch of 10 boards made so i have 8 bare boards left...if you wanted to find a way to power the pre board and work out the phantom, metering and enclosure yourself I could be talked into getting rid of a few maybe...I'm planning on doing a solid brass plate enclosure so it'll be heavy-duty once I get the other circuits done and get to the box level design...I was thinking about using mini-XLRs but passed on the idea because everybody would have to get new cables made...although it was encouraging that somebody made a req for them Other than that, some of you migh know that i am also the 'engineering' half of custom connects, making the VX pocket lo-profile coax I/O, headphone cables, so I've been lurking on here for a while....old habits die hard, i've been lurking in newsgroups since the 80s feel free to drop me a line via email: nmz77@yahoo.com 

l8r...Nick


hmmm, no pic in the preview?! hopefully it will be attached to the post....

The pic you sent me before is nicer!

-K

[VA_TAPER]

discrete powered dual-servo 990 based pre-amp...discrete powering for the rails and 48v via series miniature 12v or 6v sla's, jensen transformers in.  Modular design with jensen transofrmers and optional tape head compression circuit out, or direct to AKM a/d both as added cards to be swapped out of the feed from the 990's.

I've been working schematics on this for a while....still don't have it all done yet working from the deane jensen reference design + akm's proto board and a nakamichi record and play head ( probably to become an ampex in 1/4" 2-track head in the final design.)

peace, chris

[tubehead]

The 'green pre' project looks pretty nice, although the choice of a discrete BJT with the 5532 is an odd one, FETs would be way better to use, higher impedance and lower noise...that one has a balanced line driver on the output too, but I didn't think that was really necessary because most people use short (or super-short) cables to go from their pres to A/D or deck...the V2 has a nice line driver in it too but it's for doing a remote preamp setup, which is basically a niche application for permanent installations or venues etc.  I was also thinking about doing a swept gain setting, because doing the switched attenuator is kind of a bear to do, but it's a better solution...you can't use a standard pot to replace the attenuator because it requires a really goofy (nonlinear) curve to have a constant gain reduction per degree of rotation, so to do it you'd have to fix the gain of the amp and use a pot as a voltage divider after the gain stage - a bit noisier but also a bit easier to operate and trim in...still an option at this point tho.

the guy who posted the 990 comment, a 990-type discrete opamp would be really bad for a battery powered pre because of the power dissipation, those are usually class AB or (gasp) class A so they're burning off 75% of your battery power as heat - think AD-1000.  Transformers are nice to use, but they are what they are...expensive and fairly large but inherently DC blocking and bandwidth (noise!) limiting...one jensen transformer costs as much as 2 channels of my pre including board, parts and all...

[kennedy]

Hey y'all this is my micpre that i've been working on, still in R+D tho at this point...in the pic the preamp PCB is stuffed and working, the smaller board is the AC power supply on a proto-board (in debug) and not in the picture are the metering circuit and phantom power supply which I have designs for on paper but no physical prototypes yet...I had planned it to be an AC powered studio device initially with a portable version to be developed later - the phantom supply is way easier to design using AC and a step-up transformer so I figured I'd go for that first...but due to time constraints both have been put on the back burner...on top of that I'm starting grad school in the fall so my free time is pretty skinny, but if there is enough interest I can pick up development again...the design is a one-gain stage minimalistic design using high quality parts - film caps, the same instrumentaion amplifier (burr brown INA103) as the V2, stepped gain settings etc. It sounds really clean and open, even with the bench supply I was using...bandwidth in the 100kHz+ range, balanced in, single ended output that can be used balanced because of a nifty impedance mirror circuit I found on shure's (or jensen's?) website...I had a batch of 10 boards made so i have 8 bare boards left...if you wanted to find a way to power the pre board and work out the phantom, metering and enclosure yourself I could be talked into getting rid of a few maybe...I'm planning on doing a solid brass plate enclosure so it'll be heavy-duty once I get the other circuits done and get to the box level design...I was thinking about using mini-XLRs but passed on the idea because everybody would have to get new cables made...although it was encouraging that somebody made a req for them Other than that, some of you migh know that i am also the 'engineering' half of custom connects, making the VX pocket lo-profile coax I/O, headphone cables, so I've been lurking on here for a while....old habits die hard, i've been lurking in newsgroups since the 80s feel free to drop me a line via email: nmz77@yahoo.com 

l8r...Nick


hmmm, no pic in the preview?! hopefully it will be attached to the post....

what up nick? sounds like a great idea. welcome to the board 
hit me up if your still in need of an audio program 
peace, jk

[Nick's Picks]

this all sounds very good to me.
I'd like to see some custome designs start floating around.

I also had a defunct Ps2 that I thought about deconstructing in to something preamp flavored.  but I just ended up customizing it instead.

[muj]

TRANSFORMER  is important for me (re: PA taping), as it helps de-emphasize the room aspect in the recording, making a more focused recording. An A-B based pre-amp would be great, Transformer coupled input stage and ic based output or second gain stage, and dc powered external power supply.

[Church-Audio]

The transformer does what? de-emphasizes a room what does that mean?

TRANSFORMER  is important for me (re: PA taping), as it helps de-emphasize the room aspect in the recording, making a more focused recording. An A-B based pre-amp would be great, Transformer coupled input stage and ic based output or second gain stage, and dc powered external power supply.

[muj]

The transformer does what? de-emphasizes a room what does that mean?

TRANSFORMER  is important for me (re: PA taping), as it helps de-emphasize the room aspect in the recording, making a more focused recording. An A-B based pre-amp would be great, Transformer coupled input stage and ic based output or second gain stage, and dc powered external power supply.

the transformerless pre-amps i have used capture more room sound, the transformerbased helps to focus more on the p.a sound while decreasing  the room sound, i.e more focused recording.

hope that helped

[Chuck]

...this should be good... 

[Church-Audio]

Is that a joke? Your actually going to tell me that a transformer some how magically changes the acoustics of the room? WOW where can I get these magic transformers :_)

I think what you mean to say, I hope anyway is that because the ALL transformers are not linear that they tend to cut off low frequencies around 20to30hz and High frequencies around 18-20k (depending on the quality) And that your are hearing in fact "less of the room"

I think what you mean is that the transformers that you are using are CUTTING your extreme spectrum frequencies and thus giving you the perception of a lack of room in your recordings. Humm sounds like you need to spend more money on better transformers IMO I want my preamp to capture 100% of what is going on I will decide later on in post what to exclude. That way I don't have my gear deciding for me what I can and can not record.

Chris Church




 

The transformer does what? de-emphasizes a room what does that mean?

TRANSFORMER  is important for me (re: PA taping), as it helps de-emphasize the room aspect in the recording, making a more focused recording. An A-B based pre-amp would be great, Transformer coupled input stage and ic based output or second gain stage, and dc powered external power supply.

the transformerless pre-amps i have used capture more room sound, the transformerbased helps to focus more on the p.a sound while decreasing  the room sound, i.e more focused recording.

hope that helped

[muj]

well Chris..i am not going to spend time here debating the quality of the transformers, but i stand behind my findings 

[poorlyconditioned]

well Chris..i am not going to spend time here debating the quality of the transformers, but i stand behind my findings 

I think we have to consider at least three different things when evaluating gear:
- experience in the field (including listening to others' recordings)
- audio theory/specs
- extensive testing to make sure things actually work according to specs!

It is too easy to get buried in one or other of these and forget the others.  For example, a lot of people are recording directly into line in on the NJB3 or iRiver without testing extensively (or comparing to other options that may have less distortion).  Similarly, some people (myself included!) have done mods (eg., UA5) thinking they sound OK, only to discover that the waveforms are waaay out wack.

Really, there is no point in paying a lot of money (like we all do) and not getting the most out of our gear

On this topic, I'm looking forward to hearing how the R09 works in the field.  Hopefully someone will test it soon...

  Richard

[Church-Audio]

I know all about the different quality transformers I use them all the time. I am not argueing that good transformers sound better. What I am saying is that there is no way in hell a transformer can change the accoustics of a room. PERIOD maybe you should say that it creates a warm sound or maybe say it changes the orginal sound but it does not change accoustics. I am not trying to argue I just wanted to point out that there is no way for a transformer to change accoustics in a room. Or make a live recording sound more direct. Unless we are talking about frequencey response then I can say yes some change sound more then others but never accoustics.
Please do not take offence.


Chris Church

well Chris..i am not going to spend time here debating the quality of the transformers, but i stand behind my findings 

[bluegrass_brad]

Please do not take offence.


Chris Church

Maybe if you would word your replies to posts that are dissenting of your opinions with a little more civility no one would take offense.  Anytime anyone challanges your opinion your replies come across like your all bent out of shape and are very condescending. 

Is that a joke? Your actually going to tell me that a transformer some how magically changes the acoustics of the room? WOW where can I get these magic transformers :_)

[Church-Audio]

 I am sorry when I hear a statement like the one I responded to well, I really did think it was a joke.
I guess he was serious wow what can I say. Except how can anyone say a transformer changes acoustics? Please show me the AES paper on acoustics and transformers. I would love to read it. I am just as entitled to my opinion as anyone here. I was not calling him an idiot or a moron I just disagree. I wish that some of the people around here that disagree with me would do so in a more civil way but that does not happen very often so I guess I have adapted the T.S way of responding to things I do not agree with. I don’t think to many people can argue if you say the wrong thing people tend to jump on you around here I was just making a statement I did not make it personal there for I do not think I did anything wrong. This is still a free country right?
Chris Church

Please do not take offence.


Chris Church

Maybe if you would word your replies to posts that are dissenting of your opinions with a little more civility no one would take offense.  Anytime anyone challanges your opinion your replies come across like your all bent out of shape and are very condescending. 

Is that a joke? Your actually going to tell me that a transformer some how magically changes the acoustics of the room? WOW where can I get these magic transformers :_)

[it-goes-to-eleven]

How hard can it be to copy the Portico?

[Chuck]

This is still a free country right?

Chris Church

Well, the US is anyway... 

[bluegrass_brad]

I wish that some of the people around here that disagree with me would do so in a more civil way but that does not happen very often so I guess I have adapted the T.S way of responding to things I do not agree with.

Maybe because you always get bent when someone disagrees with you and then get all whiney and condescending.  You do make it personal when you make comments like "wow show me these magic transformers!". That statement in my opinion is implying that MUJ is a dumbass for thinking something different than you.  I also never saw him mention the word "acoustics" at any time.

[muj]

I am sorry when I hear a statement like the one I responded to well, I really did think it was a joke.
I guess he was serious wow what can I say. Except how can anyone say a transformer changes acoustics? Please show me the AES paper on acoustics and transformers. I would love to read it. I am just as entitled to my opinion as anyone here. I was not calling him an idiot or a moron I just disagree. I wish that some of the people around here that disagree with me would do so in a more civil way but that does not happen very often so I guess I have adapted the T.S way of responding to things I do not agree with. I don’t think to many people can argue if you say the wrong thing people tend to jump on you around here I was just making a statement I did not make it personal there for I do not think I did anything wrong. This is still a free country right?
Chris Church

Please do not take offence.


Chris Church

"Except how can anyone say a transformer changes acoustics?"


never said that. The thing is you interpreted what i wrote that way.  Now i could have modified my post and write a full page , explaining what i meant.  

but nah...

[Brian Skalinder]

I am sorry when I hear a statement like the one I responded to well, I really did think it was a joke.
I guess he was serious wow what can I say. Except how can anyone say a transformer changes acoustics?

FWIW, I've found you're pretty quick to get bent out of shape due to a simple misunderstanding, Chris.  I read Muj's statement...

TRANSFORMER  is important for me (re: PA taping), as it helps de-emphasize the room aspect in the recording, making a more focused recording.

...as suggesting that the sonic characteristics of the transformers help minimize, to his ears, the room ambience.  Maybe that means the highs and lows are rolled off, as you suggest, I don't know.  But regardless, it's quite clear to me that he's not suggesting the transformers actually impact the acoustics of the room itself, as you suggest.

Instead of drawing incorrect conclusions or making incorrect assumptions and (IMO) insulting people, maybe try asking questions to ensure you properly understand others' intent.

[muj]

ok...people ..i love y'all let's not turn into a drama...though i love it.


i said earlier that in my experience taping concerts , i have come to the conclusion that a high quality
transformer balanced mic pre-amp is more ideal than say a tranformerless ( higher speed and bandwidth) pre-amp.

In my experiences the end result using a transformer based pre versus a transformerless, is that the transformer balanced mic pre masks or de-emphasizes the room aspect in the recording/ tape. A transformerless pre-amp like the cranesong flamingo can add color by 2 switches and still retain the room aspect in the recording.

In my experience a transformer based pre-amp have more "focus" on the sound source
(again depends on what pre-amp is used)

As far as what i pre-amp i use or not use, there is nothing to brag about. or what kind of transformers i use.

 

[muj]

I am sorry when I hear a statement like the one I responded to well, I really did think it was a joke.
I guess he was serious wow what can I say. Except how can anyone say a transformer changes acoustics?

FWIW, I've found you're pretty quick to get bent out of shape due to a simple misunderstanding, Chris.  I read Muj's statement...

TRANSFORMER  is important for me (re: PA taping), as it helps de-emphasize the room aspect in the recording, making a more focused recording.

...as suggesting that the sonic characteristics of the transformers help minimize, to his ears, the room ambience.  Maybe that means the highs and lows are rolled off, as you suggest, I don't know.  But regardless, it's quite clear to me that he's not suggesting the transformers actually impact the acoustics of the room itself, as you suggest.

Instead of drawing incorrect conclusions or making incorrect assumptions and (IMO) insulting people, maybe try asking questions to ensure you properly understand others' intent.

thanks for that. you got it. And i apologize , I should have written more clearly what i meant. Still jet lagged from 14 hours of flying...

[Church-Audio]

Hey its all good I am sorry I did not mean to sound like a dick I was just poking some fun at the statement.

ps YOUR not the only one that says stupid shit after a long flight I am the master of saying stupid shit just read half of my posts lol

Anyways thats all I was saying about the transformer thing I love the sound of transformers my fav Neve preamps have transformers in them. I think that is why they sound as good as they do.

Again I am sorry for responding the way I did. I thought it was funny at the time but I guess its not. No one ever gets my dry sence of humor except me

Chris Church

I am sorry when I hear a statement like the one I responded to well, I really did think it was a joke.
I guess he was serious wow what can I say. Except how can anyone say a transformer changes acoustics?

FWIW, I've found you're pretty quick to get bent out of shape due to a simple misunderstanding, Chris.  I read Muj's statement...

TRANSFORMER  is important for me (re: PA taping), as it helps de-emphasize the room aspect in the recording, making a more focused recording.

...as suggesting that the sonic characteristics of the transformers help minimize, to his ears, the room ambience.  Maybe that means the highs and lows are rolled off, as you suggest, I don't know.  But regardless, it's quite clear to me that he's not suggesting the transformers actually impact the acoustics of the room itself, as you suggest.

Instead of drawing incorrect conclusions or making incorrect assumptions and (IMO) insulting people, maybe try asking questions to ensure you properly understand others' intent.

thanks for that. you got it. And i apologize , I should have written more clearly what i meant. Still jet lagged from 14 hours of flying...

[Javier Cinakowski]

Everyone sounds like an asshole from time to time.  What I like about Chris Church is he admits it.     Now that everyone has appologised please get back to work building the sickest preamp ever.  Thanks!!!     

[phanophish]

I think this thread might have been titled, Let's build a perfect religion.  We will never get everyone to agree on something so subjective, but that's what makes trying so much fun.........

[tubehead]

ouuuch! 'let's build a flame war'

back on the subject! here's the main parts of a mic preamp:

input/unbalancing section           can be transformer (easiest but costly) or solid state (be careful of CMRR)
gain stage                                opamp(DMIC, other mid-grade pres), instrumentation amp (V2), discrete(Oade pre, neves, millenia?!)
gain control                              can be part of amp stage, or pre- or post- attenuator, stepped or swept
metering                                  no meters, clip lite, analog vu, LED bar graph
headphone amp                        some do, some don't
power supply/batteries               runs off of either +6 or +12, so a switching converter is usually needed, sometimes 2 9v's are used for +/- rails
phantom supply                         a nicety, usually done with another DC-DC convterter, could be a source of noise if done wrong...
output line driver                       optional, the one in the V2 can drive 1000m of cable, but field tapers will never use that...

many, many ways to do all of the above...first thing is choose the topology of the preamp, what is going to be included.
from there there are lots of designs to start with, helpful app notes (jensen, burr brown, national etc.) that give design
suggestions, work with those, build a prototpye. sound test it, find areas of improvement (fix what's broken!)
spin. retest....find a box for it all...

dunno if any of you were on the diy-hdrec list, a similar group trying to make a hard drive based recorder....a few smart guys on there, but scope
creep killed it...i want this...i want that etc. the only way to get something realized is to limit the scope early, get something working then ADD things
to your WORKING prototype. start simple and embellish. or make a basic model that can be built up in different ways. this can be done as an amp core,
then couple it with your preferred method, power supply etc. maybe make a bunch of small boards that plug together or pin compatible?? maybe do a main
amp board for SS balancing, one main board for XF balancing, then make the power supply, metering, headphone amp and output boards plug into that?
kind of a modular approach...maybe even include space for a *GASP* digital board?

[muj]

i would like to see the lundahl LL7903 on the input stage followed by audio upgrades high speed card or IC stage...

[udovdh]

ouuuch! 'let's build a flame war'

Indeed.
I don't need a pre.
I can vary the signal with a simple resistor.
I might just need an impedance buffer. I'm trying one this weekend.

I just built a proof of concept. It works but I need help on proper implementation details.
(sizing of a resistor)