RE: Got one more amp finished to an initial degree.

OTL Asylum

OTL, Output Transformerless Amplifier User Group.

Posted by kbsp on July 8, 2016 at 08:48:51

In Reply to: Got one more amp finished to an initial degree. posted by jeffreybehr on April 26, 2016 at 22:24:58:

Hi,

Bypassing have been long term best practice for us amateurs but I'm not too sure that it's a good idea after all.

Real world capacitors are capacitors with unavoidable small inductance and resistance so we should design our circuits with that in mind that they indeed are resonators at a given frequency.

By paralleling (different values) of capacitors might interact with each others like a parallel resonant circuit. Our perception of an improvement by the added capacitors might not be an improvement after all. Verifying the implementation by measuring the circuit before and after can give us a hint.

So, I believe your intention by replacing the originally 150uF capacitors is the better approach.

For my own DIY M60 I've installed 4-pole electrolytic capacitors followed by electronic chokes followed by polypropylene capacitors. No bypassing.
It does measure excellent for sure but is it really a better implementation soundwise compared to Ralphs approach? Maybe, maybe not.

Ralphs passive PSU design is guaranteed to be long stable solution without any risk for a meltdown of the output tubes nor our beloved bass drivers.

BR.

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Follow Ups Full Thread

Topic - My experiences with new M-60 Mk.3.3s, good and not-so-good - jeffreybehr 14:28:07 04/23/16 (11)

RE: My experiences with new M-60 Mk.3.3s, good and not-so-good - ozzyboy 12:07:04 03/16/17 (0)

Winter-'17 bump. Got the new front-wall dampers installed... - jeffreybehr 14:53:40 02/27/17 (0)

My latest adventure with these amps had one OT blowing its internal fuselinks. - jeffreybehr 17:34:29 07/07/16 (0)

The system sounds better all the time. - jeffreybehr 01:03:43 05/13/16 (0)

Got one more amp finished to an initial degree. - jeffreybehr 22:24:58 04/26/16 (2)

RE: Got one more amp finished to an initial degree. - kbsp 08:48:51 07/08/16 (0)

RE: Got one more amp finished to an initial degree. - Leadfoot 18:51:10 04/27/16 (0)

RE: My experiences with new M-60 Mk.3.3s, good and not-so-good - Lew 10:04:10 04/25/16 (2)

Lew, of course the amps came with feet; I removed them. :-) - jeffreybehr 18:43:40 04/25/16 (1)

My mistake... - Lew 21:51:59 04/25/16 (0)

RE: My experiences with new M-60 Mk.3.3s, good and not-so-good - Cousin Billy 08:02:11 04/25/16 (0)

Follow Ups

RE: Got one more amp finished to an initial degree. - kbsp 08:48:51 07/08/16 (0)

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