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Old 12th February 2009, 06:12 PM   #1
Sony is offline Sony  Europe
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Default Aleph P - Tape Out as Main Out

Cheers!

What would be the 'cleanest' way of converting the Tape Out to a second Main Out on Pass Aleph P, last version?

Thanks and regards!
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Old 13th February 2009, 01:45 AM   #2
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Isn't the tape loop in this pre-amp a direct connection between the input and the output? I guess I'm not sure what you're looking to accomplish. Do you want to drive 2 amplifiers for bi-amping or something?

Is this a factory unit or DIY?

-David
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Old 13th February 2009, 08:29 AM   #3
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David, thanks for the reply.

That is so. I want to bi-amp and use two outputs by converting the tape loop (which I don't use) into a second main-out.
The tape out is connected to the input and I want to connect it to the output. Quite simple.

The question is not 'what' but 'how', I mean how to do it phisically with the aim of not to mess too much with the unit and to get the best sonic results.

It is a factory unit, last version:
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File Type: jpg pass aleph p inside tape main.jpg (18.6 KB, 250 views)
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Old 13th February 2009, 12:06 PM   #4
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Hi,

without looking at the schematic, I can already remind you that Tape-Out is not affected by volume control and you don't want that right?

Paralleling amps can also be a little complicated if they have small input impedance. Even more complicated if they have different gains.

If you're fearless, you can solder yourself a 1->2 cable - has the nice sideeffect that you don't need to touch your nice Pass-pre.

Have fun, Hannes
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Old 13th February 2009, 02:09 PM   #5
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Thanks Hannes!

I may be wrong on this, but based on Aleph P circuit tipology and ultra-low output inpedance there should be no problem with low input impedance amplifiers.
For instance, paralleling two amps with 23Kohm input impedance each would result in a final impedance of 11kohm.

Since I don't use the tape out, it's more 'elegant' for me to modify the Aleph P than to use a 1->2 cable. Also I expect to keep the Aleph P for eternity.
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Old 13th February 2009, 03:34 PM   #6
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Hi Sony, I agree with Hannes that a 1-->2 custom cable is the best solution. The only other option is to start cutting PCB traces and soldering jumpers, which is not elegant. The resale value of the unit drops dramatically if it is altered.

There are also potential options like home theatre applications at some point where you might want the tape out someday.

Get 4 cables of the right length and unsolder the preamp end on two of them and join them to the other. Very clean.

-David
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Old 13th February 2009, 03:59 PM   #7
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David, thanks again.

The tape out is usless because I can always use a 1->2 custom cable to connect the source to both the Aleph P and Tape.

One important advantage: If I use a pair of outputs I gain total flexibity in trying diferent quality interconnects.

Are you sure that to cut PCB traces is the only solution?
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Old 14th February 2009, 04:45 AM   #8
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If you don't feel like making such a cable, you can get pre-made adapters such as a Connex Y-adapter from Parts Connexion here:

http://www.partsconnexion.com/catalog/connectors.html

(Just search the page for 55457 - its part number.)

-j
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Old 14th February 2009, 09:39 AM   #9
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To get all of the benefits of bi-amping, you just use the main outputs to drive an active crossover, bypassing the passive crossover.

Something like this:

PRE
|
Active XO ----- Amp 1--- Tweeter or top end bypassing high pass at the lowest XO frequency
|________Amp 2 --- Woofer
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Old 14th February 2009, 05:02 PM   #10
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Default Re: Aleph P - Tape Out as Main Out

Quote:
Originally posted by Sony
Cheers!

What would be the 'cleanest' way of converting the Tape Out to a second Main Out on Pass Aleph P, last version?

Thanks and regards!
You asked the forum for the "cleanest" way to get a second output for bi-amping. 1-->2 cable is the answer. If you are still determined to hack a beautiful piece of hardware to accomplish this, then go for it.

Bob Ellis is also correct. The main benefit for bi-amping is to eliminate speaker crossovers. An active crossover is needed, and this device will have 2 or 3 outputs per channel for amp connection.

-David
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