My pre-amp has a true, balanced, design but my CDP has unbalanced (single ended) outputs. To deal with this difference I've just used some interconnects with XLR on one end and RCA on the other end. Is it possible to convert the unbalanced output of the CDP to a balanced signal prior to input to the pre-amp? And, if so, then how is this best done? I've read some posts about use of Jensen transformers but, having little experience in DIY electronics, I don't fully understand this option as most look to do voltage conversions. Thanks for the assistance and the reason for the interest is that the system into a new room that requires longer interconnects in a much more electrically noisy environment (behind an entertainment unit below a plasma screen).
Regards
APS
Regards
APS
This might get you going:
Neve 1272 Preamp
It would act like a output buffer too which would help in long runs. The opamp he picked is a very good one. The power supply is alittle tricky but the opamp can work at 12 volts so you could use one of several designs such as ambs mini3.
Mind you all this is, is a rca to balanced converter thats happening inside your cd player. Depending on the cd player you might just be able to find a balanced single and just buffer it.
Neve 1272 Preamp
It would act like a output buffer too which would help in long runs. The opamp he picked is a very good one. The power supply is alittle tricky but the opamp can work at 12 volts so you could use one of several designs such as ambs mini3.
Mind you all this is, is a rca to balanced converter thats happening inside your cd player. Depending on the cd player you might just be able to find a balanced single and just buffer it.
It would be FAR simpler an MUCH more sonically transparent to simply use an Analog Devices SSM2142 balanced line driver, if you are up to building a simple circuit board. If not, then the best way to go unbalanced to balanced is to go to the Jensen Transformers website & pick out one of their transformer-based converter boxes for the purpose. Pricey, but they make the best transformers currently available.
Really? The antique NE5532 is a "very good one"? better than other jellybeans, yes. Very good... not.
Do you know if your preamp's inputs use input transformers?
If so, then there's really not much need to convert your CDP's output to balanced as input transformers will give you good common-mode rejection even when fed from unbalanced sources.
se
If so, then there's really not much need to convert your CDP's output to balanced as input transformers will give you good common-mode rejection even when fed from unbalanced sources.
se
Well do you have an opamp hierarchy list? hes fine with stock rca outs but wants a longer run and to take advantage of his balanced ins.
AD8620
LME49720/LM4562
LM4562 is my favorite for dual opamps.
I was ready to suggest that, but then I saw this in his first post:
I don't expect changing the analog stage following the DAC is at his expertise level.
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If your player's output impedance is low enough (<300ohms), an output trafo such as a Jensen JT 11-em would fit the bill. Pretty much plug and play too. Just keep the connections from the player to the trafos as short as possible.
I would recommend getting Line transformers from Onetics/Bud purvine (BudP) here on the forum over the comparatively expensive Jensens, not much difference in SQ, but price is quite different and you can get it custom made to suit the gain you need and impedance match your gear.
If I get another pr, BudP's trafos will be the ones, but $56 for the Jensen isn't that bad. Shipping will cost $$ any way you go.
If you want to mod your player, then there are direct IC solutions that are very easy to implement and you will get much better performance than trying to cook up something with an Op Amp!
For instance:
DRV134
SSM2142
et cetera.
You can likely just install one internally on a small IC prototyping PCB and tie it in to the existing PS rails.
-Charlie
For instance:
DRV134
SSM2142
et cetera.
You can likely just install one internally on a small IC prototyping PCB and tie it in to the existing PS rails.
-Charlie
Bill,
I sent an e-mail to sales @ Jansen trying to get two JT-11-BMCF but haven't heard from them...
Do you have a reliable supplier for Jensen transformers?
Have you had any experience with BudP's transformers? Are they of the same sound quality and more importantly, are they easy to order?
Thanks,
Boky
I haven't purchased anything directly from Jensen, but I know of people that have. They seem to be a little slow with their emails.
I did get a couple emails from Bill Whitlock, it took him a week or so to respond.
Markertek sells the Jensen line, and I think B&H and Full Compass also.
It would seem that 11-BMs would be overkill for a dac application but what the hell!
Just PM BudP if you're interested in his trafos. I have heard positive opinions but no first hand experience.
I did get a couple emails from Bill Whitlock, it took him a week or so to respond.
Markertek sells the Jensen line, and I think B&H and Full Compass also.
It would seem that 11-BMs would be overkill for a dac application but what the hell!
Just PM BudP if you're interested in his trafos. I have heard positive opinions but no first hand experience.
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