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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: ts on April 24, 2022, 10:02:45 AM

Title: Transformerless preamps?
Post by: ts on April 24, 2022, 10:02:45 AM
Do we have a list of those without transformers? I know Grace and Sax SX-M2 are. Is the Beyer MV100 also on the list? What else? Sound Devices 7xx and Mix Pre all in ones. Tascam 70d? Thanks.
Title: Re: Transformerless preamps?
Post by: heva on April 24, 2022, 03:11:29 PM
Beyerdynamic mv100 is transformless
Title: Re: Transformerless preamps?
Post by: morst on April 24, 2022, 03:12:39 PM
Beyerdynamic MV100 manual says it's got electronically-balanced inputs.
https://taperssection.com/index.php?topic=103430.msg1379146#msg1379146 (https://taperssection.com/index.php?topic=103430.msg1379146#msg1379146)


it weighs 435g with batteries
Title: Re: Transformerless preamps?
Post by: fanofjam on April 26, 2022, 06:57:38 AM
If I remember correctly, one of the main differences between the Oade M148 and M248 is that the 248 was sans transformer. 

I'm a little less clear on this, but I think that one time I read that the PSP3 was without, while the PSP2 was with.
Title: Re: Transformerless preamps?
Post by: ero3030 on April 29, 2022, 10:29:10 AM
Oade 248 transformerless gold. 
Title: Re: Transformerless preamps?
Post by: yug du nord on April 29, 2022, 05:00:41 PM
Oade 248 transformerless gold.

Aeta PSP3
Schoeps VMS
Sound Devices USBpre2
Edirol UA-5

Most all-in-one recorders are transformerless I think.
Title: Re: Transformerless preamps?
Post by: DSatz on May 01, 2022, 01:29:38 AM
It might actually be easier to list which preamps have input transformers. Sound Devices preamps are big exceptions by having them. By far most other portable, solid-state preamps are transformerless.
Title: Re: Transformerless preamps?
Post by: H₂O on May 02, 2022, 09:08:59 PM
Oade 248 transformerless gold.


I thought the Oade 248 had output transformers?
Title: Re: Transformerless preamps?
Post by: ero3030 on May 03, 2022, 06:05:43 PM
Oade 248 transformerless gold.


I thought the Oade 248 had output transformers?
148( the brick) was the warm pre . Not my cup of tea. I deff miss all the flavors of pre's we all used 20 years ago. Anyone else miss the deff flavors?
Title: Re: Transformerless preamps?
Post by: fanofjam on May 04, 2022, 06:52:29 AM
Oade 248 transformerless gold.


I thought the Oade 248 had output transformers?
148( the brick) was the warm pre . Not my cup of tea. I deff miss all the flavors of pre's we all used 20 years ago. Anyone else miss the deff flavors?

Yes...me.  I've decided that when I get out and start taping again that I'm putting my preamps back into play.  I got lazy and spent the last couple years before pandemic going direct into my mixpre3, but those recordings just don't have the special sauce.  Still have my Oade m118, a couple of Schoeps VMS's and recently picked up an old RAD MS-2 from goodcooker on the cheap...those are all going back into play.
Title: Re: Transformerless preamps?
Post by: ero3030 on May 05, 2022, 07:55:44 AM
Oade 248 transformerless gold.


I thought the Oade 248 had output transformers?
148( the brick) was the warm pre . Not my cup of tea. I deff miss all the flavors of pre's we all used 20 years ago. Anyone else miss the deff flavors?

Yes...me.  I've decided that when I get out and start taping again that I'm putting my preamps back into play.  I got lazy and spent the last couple years before pandemic going direct into my mixpre3, but those recordings just don't have the special sauce.  Still have my Oade m118, a couple of Schoeps VMS's and recently picked up an old RAD MS-2 from goodcooker on the cheap...those are all going back into play.
I totally miss checking out others peeps recordings, especially the ones with different pres using my mics. Was the only way to buy gear. Listening to different mics , pres, and diff venues.  Now 90% of peeps run the same all in one. And don't get me started on ADC'S.  remember carrying those around also!!!!?? Lol. Keep rocking those different flavors!!
Title: Re: Transformery preamps!
Post by: morst on July 02, 2022, 10:30:06 PM
here are two which are *not* transformerless.

The Shure FP24 is a studio-quality two-channel, portable, stereo microphone mixer.
(blah blah blah)
* SNIP! *
• Premium Lundahl input transformers provide superior audio quality and freedom from interference problems.


and the D

The MixPre-D Compact Field Mixer from Sound Devices is a versatile audio mixer built for the digital age. Based on the popular MixPre, the "D" in the name indicates the extensive digital technology that's been incorporated into the mixer.
* snip!!! *
Based on the popular MixPre mixer, with additional digital technology to meet the changing needs of the current production landscape
Studio-grade transformer-balanced mic/line XLR inputs with unclippable peak limiters, 80/160Hz high-pass filters, and 48V or 12V phantom power allow you to connect a variety of input devices

Title: Re: Transformerless preamps?
Post by: goodcooker on July 04, 2022, 01:38:02 PM

recently picked up an old RAD MS-2 from goodcooker on the cheap.

That Reference Audio Designs preamp is transformerless, has the exact same chipset at the PSP3 and has a custom designed DC to DC converter. It's dead quiet and has a beefy present sound that works really well with darker mics like Schoeps, Peluso and ADK TLs.

I bought it from stirinthesauce many years ago, sold it to Chris Davis then bought it back from him then sold it to you.
Title: Re: Transformerless preamps?
Post by: Chilly Brioschi on July 08, 2022, 11:35:44 AM
Out of curiosity, TS, why do you want to avoid audio transformers ?


I have found a power module that could make the AEA TRP2 battery-powered portable.
JFET, no transformers there.  (verifying)

If transformers *are* your bag, I stumbled on something interesting with dual Cinemag (Reichenbach) transformers per channel.
70db of gain, clone of a Neve design, I believe.

The same team is also doing a tube model:


(https://www.soundskulptor.com/prodimages/mp566blocdiagr.jpg)


All available as kit or assembled
All are Mono units which can be ganged
Title: Re: Transformerless preamps?
Post by: ero3030 on July 08, 2022, 07:25:24 PM
Out of curiosity, TS, why do you want to avoid audio transformers ?


I have found a power module that could make the AEA TRP2 battery-powered portable.
JFET, no transformers there.  (verifying)

If transformers *are* your bag, I stumbled on something interesting with dual Cinemag (Reichenbach) transformers per channel.
70db of gain, clone of a Neve design, I believe.

The same team is also doing a tube model:


(https://www.soundskulptor.com/prodimages/mp566blocdiagr.jpg)


All available as kit or assembled
All are Mono units which can be ganged
For me, too warm. Like my recordings crispy and in the bright side. Tube amp at home can warm things up if needed/wanted.  Deff a personal preference.  Miss the pre amp swapping days
Title: Re: Transformerless preamps?
Post by: Chilly Brioschi on July 08, 2022, 07:39:04 PM
^^ think  Aretha Franklin
    Sweet vocal, present, not pronounced bottom, and smooth at the top
Would roll the tube version on a set of KM184 or AKG C1000S
They also have the dual-transformer in a solid state model as well, no diagram found.

"Tube sound" mostly happens in the PA stage, but certainly can be evident in a pre.

There are a few Phish recordings made with tube gear... mic's and Pre's.
Title: Re: Transformerless preamps?
Post by: ts on July 08, 2022, 08:25:47 PM
Did I sound like I was looking to avoid transformers? Not at all. I was mostly curious about the MV100 and thought maybe a list would be a good idea. But as dsatz pointed out, probably easier to make the other list.
Title: Re: Transformerless preamps?
Post by: checht on July 08, 2022, 09:11:30 PM
[snip]
If transformers *are* your bag, I stumbled on something interesting with dual Cinemag (Reichenbach) transformers per channel.
70db of gain, clone of a Neve design, I believe.
Inspires me to share a little history: In '83, used km84is from Wally Heider Studios in hand, I set out to improve upon the 2-D cell p48 plus Tandy xlr->1/4" decouplers in common use ahead of the D-5m. I liked the Neve sound, so just called 'em, asked for an engineer, explained my use case, and requested help. He thought it so weird that he was inspired and sent a diagram that used Jensen transformers. I cold-called Jensen, found a sympathetic engineer, and he helped me select a transformer for decoupling from p48 and also with enough gain that I could run line in. That design, plus 6-9v batteries and a couple caps and resistors for p48, became the black box that I sold to tapers using Neumanns. Financed my touring habit for years, and I could build them while on tour after demo'ing them in the section for tapers around the country. Doug Oade, an engineer who actually knows what he's doing, took the idea and radically improved it by adding a sophisticated active section, and that design is, as far as I know, the origin of his transformer-based line.
Title: Re: Transformerless preamps?
Post by: Chilly Brioschi on July 08, 2022, 10:00:45 PM
That is TaperSection History and belongs in some sort of legacy statement, a book, a comprehensive article, something...

The phantom "B+ battery" makes me smile, thinking of the ARC Swap Meet  (http://www.njarc.org/)tables with A, B, and C batteries lighting up old early 20th century tube radio receivers.

Did we even imagine that the PR2301 phantom-on-a-chip chip would exist ?
I had breadboard Op-Amps doing digital switching logic puzzle toys, but no imagination to a charge pump regulator, or anything close.


Did I sound like I was looking to avoid transformers? Not at all. I was mostly curious about the MV100 and thought maybe a list would be a good idea. But as dsatz pointed out, probably easier to make the other list.

Curiosity, no way criticism
I was wondering if there was some sonic thing or undesired artifact that you were running from or toward.  :shrug:
The new digital modeling really changes the game.
Moore's Law of Computing starts to affect digital audio, so I expect changes that I might not be able to keep up with....    :facepalm: