DRV134 instead of JT-123-DBX

[bigugly]

Hey,

I just received a bunch of samples from TI including the DRV134. I used the schem in the app note to make a small board that has the same pinout as a JT-123-DBX. I am planning on using this in my 312 clone which is straight from Group DIY-Project 2 pdf with the addition of a DIP8 socket under the DOA so I can test out different opamps. (5534, OPA604, OPA627, OPA637, AD797, and Avedis 1122)

My question is if I need a coupling cap on the input to the DRV134 seeing as how each one of these amps has a different DC offset? Also would I need a resistor in series with the input? Thanks in advance.

James
Big Ugly Van Audio

 

[Kev]

I think I know where you are going but I also think you may have quoted the wrong part ???
:?
I could be getting all this wrong but the JT-123-DBX is the Jensen output transformer.

The pin config you are talking about is for the Gain Block ??
API2520 , 990 , Melcor 1731 etc ...
YES you can make a PCB that will fit this and into that have an IC socket to accept all the usual suspects. Don't forget to try an LM833.

A good start might be to look at Joe Malone's PCB of the JLM99x project.
http://www.jlmaudio.com/JLM99V.htm


???

wait a second ... I'm confused again ...
DRV134 is a balanced line driver ???

???
err
I'm very tired after doing more than a 12 hour shift ... so I'll shut up now. Perhaps it's time for some food and bed.

 

[bigugly]

Yeah Kev,

After reading my post a day later I can see how you could get confused. It even messed me up. :?

Yes, the DRV134 is a balanced line driver and I thought I could use this in place of the Jensen output transformer.

Is this possible? I've alredy got a couple of boards etched based on the app notes. No big deal if this won't work. The pcb'c were scap left over from cutting down the API main boards anyway. I just thought it would be cool to have an electronically ballanced output on this pre. Really I'm just to cheap to buy 8 Jensens for this project. (I'm putting 8 of 'em in a 2U rackmount)

The JLM99V is where I got the idea of the dip socket under the DOA. I've already updated the pdf from the Group DIY Project 2 with this. I'll send you the file if you want to put it up on the page.

James
Big Ugly Van Audio

 

[dale116dot7]

I'm using the SSM2142 (Analog's version) in my latest compressor project for this very purpose. Now, I don't know about the API, but the JE990 can drive a 600 ohm line directly, via a coupling capacitor - making it a single-ended output. But that works ok if you're careful on grounding and that sort of stuff. You do skip the sound of the iron, but that's ok too - you'll get a different sound. I like the idea of dual-footprinting that. You can decide to change to transformer or back as you like.

 

[Kev]

:roll:

I just feel that it is back pedalling to go from a Gain Block like a 990 to an SSM2142 or DRV134 ...

I love the SSM2142 and use it in almost everything I do here at work. See my opto comp and balancing box etc ...

With one of these gain blocks I think you want a trafo ... or go straight unbalanced.

 

[bigugly]

Cool, thanks Kev.

James

 

[SSLtech]

yeah, 990's are beautiful things in that they can supply JUICE to drive transformers and 'tame' their primaries. Doing it that way will avoid the whole "Weak-current-drive-IC" syndrome. Feeding it into a DRV134 -useful chips though they are- will likely destroy all the "Pump-me-full-of-Bass...I'm-not-scared" character of the 990.

Keep the 134s for balancing the output of 'lesser' unbalanced sources, I say! :thumb:

keith