MCI preamp mod ?

2Low · Jul 31, 2005

Hi
Is there any kind of mod for MCI 636 preamps ?
I know there´s a very reasonable replacement card from John Hardy available, but the question is: Do they sound slightly dark because of the preamp design or low quality components ?
greetings
2Low :guinness:

SSLtech · Aug 1, 2005

636... is that transformer or LM394 transistor front end?

Keith

2Low · Aug 1, 2005

Hi Keith
The manual says :
The pre-amp consists of an LM394 thermally matched transistor pair and operational amplifiers configured in an instrumantation grade differential amplifier. these differential amplifiers convert the balanced input into a single ended output signal

SSLtech · Aug 1, 2005

Okay... I think I have a couple of those. -They don't sound "dark" to me, I must say...

Anyhow, assuming it's the ones I have, there's no poor quality components on them that I've seen. Any 'sound' is in the design. You can try swapping chips for your preferred "gucci" alternative, try some additional ceramic local rail bypass caps, but the design will be the same, it will work the same way, and I don;t expect that you'll notice any real difference in performance.

Keith

tk@halmi · Aug 1, 2005

[quote author="2Low"]Hi
Is there any kind of mod for MCI 636 preamps ?
I know there´s a very reasonable replacement card from John Hardy available, but the question is: Do they sound slightly dark because of the preamp design or low quality components ?
greetings
2Low :guinness:[/quote]

Does anyone have a schematics of this preamp to share? I think I got one of these cards form Seth a long time ago. We did not know how to power it up safely and after looking at it for a while I set it aside as I did not want to blow it up.