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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: iphone on January 28, 2004, 05:58:54 AM
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hello
the sounddevices mp-2 (i used to own one) uses Lundahl LL1576 input transformers.
Lundahl makes a better transformer it's called the LL1538xl
these transformers offer lower impedance ratio,distortion level and higher input headroom( can handle higher hspl),meaning a cleaner and more transparent sound as a result.
the transformers have the same pinout as the 1576,if you want to upgrade your mp-2,i would contact sounddevices and see if they could swap and tweak your mp-2.
just a suggestion.
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cool!
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do we have any confirmation that Sound Devices would do this...? They did MD the unit...
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I sent jim williams a e-mail about it.
--m
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giddyup!
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do we have any confirmation that Sound Devices would do this...? They did MD the unit...
yes...i am interested as well, and i just called them to let them know my mp-2 is on the way for the nimh battery switch, and for a tweaking.
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yes...i am interested as well, and i just called them to let them know my mp-2 is on the way for the nimh battery switch, and for a tweaking.
What's the nimh switch allow you to do?
--hoyt
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it basically changes the spring in the battery compartment so you can use rechargeable AA batteries. i think mp-2's with serial numbers that start with 43XXXXX have it built in already, but if not you will need to have sound devices change it over...costs $25 + shipping, and worth it, IMO. while its there they also do a bench test of your unit to make sure all is well
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it basically changes the spring in the battery compartment so you can use rechargeable AA batteries. i think mp-2's with serial numbers that start with 43XXXXX have it built in already, but if not you will need to have sound devices change it over...costs $25 + shipping, and worth it, IMO. while its there they also do a bench test of your unit to make sure all is well
Ah. I haven't stealthed with the mp-2 yet, so all I've used is ecocharge power. I'll have to check it out when I get home today. Thanks! +t
--hoyt
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I just called sound devices, i don't know who i talked to, but they said that if you could get the part and if it fits then a soldering iron is all you would need to put it in. however he said that the part was not in their computer, so he did not know if it would fit. he did say that if the part fit, and you could get the part yourself, there was a chance that they would put it in for you if you sent them your MP-2 and the new parts.
So if someone finds out if the new transformers fit, i will try to order the parts and either send it to SD and try to get them to mod it, or take it to one of my professors to help me put it in (i'm an EE major).
If anyone finds out if the transformers are the same size let me know. (pinout is the same but what about height?)
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www.lundahl.se
-->mic input 1538 and 1538 xl
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the LL1538 will fit. the xl version is 3 mm higher,should also fit.
hopefully :)
Good luck and keep us informed.
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It looks like the only distributor in the US is in NC, he is selling them for $64 a piece. Can any one look at the data sheets and tell me if it will be worth the $130 it will cost me(I assume that I need two of them)?
old transformer:
http://www.lundahl.se/pdfs/datash/1576_77.pdf
new transformer:
http://www.lundahl.se/pdfs/datash/1538_8xl.pdf
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both the 1538 and the xl version,have wider bandwidth,and your pre will handle a extra db's of input level. the lundahls are cheap compared to cinemag and jensen transformers,those go over 100 dollars for 1!!
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i got these e-mails from SD today:
Thomas,
By all means you are welcome to swap parts in your MP-2. That said, Sound Devices service department performs repair service only, and only repairs to our original specification. We will repair or replace parts, as needed. Part substitution is only performed when a service part is discontinued. While Per Lundahl's (Sound Devices is Lundahl's largest single customer) new mic-level transformer may marginally improve the performance of the MP-2, we have not tested it. Since the MP-2 is discontinued, continuing-engineering has ceased on that product.
It sounds like you have an engineer who can do the work. I recommend that they document what they have modded and be able to revert back to the original state in case the mod doesn't help, or if some other voodoo occurs.
When our upcoming 722 recorder is released, you may want to take a look it. The mic preamp circuit in that product is a significant step forward in audio performance from our transformer-based topologies.
Good Luck!
Jon Tatooles
Managing Director
and this one:
Thomas,
Our chief engineer dropped me a note regarding the 1538 Lundahl part you where inquiring about. Here is a snippet,
"this transformer is not new, and it would degrade noise performance as it is a 1:5 step up instead of 1:7."
Again, you are on your own. Good luck.
Regards,
Jon Tatooles
Looks like the mod is not such a good idea.
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ok from what i understand they can not modify( because they discontiuned the mp-2) the circuitry so optimum source Impedance matches the 1538 transformer.But do you know what kind of op amp chip the unit use?
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When our upcoming 722 recorder is released, you may want to take a look it. The mic preamp circuit in that product is a significant step forward in audio performance from our transformer-based topologies.
at least there is some good news!
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i noticed that too, chase!
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it would be great if the pre and a/d sounded good, running mics > 722 would be a very compact setup.