Mainline BIAS Issue

Mike V. · 3000

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Offline Mike V.

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Reply #15 on: July 05, 2016, 11:22:40 AM
I just notice that 2 lends on the C side board takes a little to turn on
« Last Edit: July 05, 2016, 11:28:03 AM by Mike V. »

Crack w/Speedball/HD650/DacMagic-100/

Mainline (on the way)/K702/ProJect Xpression III Classic w/ DL-103R/ Speedbox/Cambridge Audio 651p/


Offline swich401

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Reply #16 on: July 05, 2016, 01:50:01 PM
On C side, you have resistors from the center lug going to 3 and 8 of the tube socket. This is supposed to be 2 and 8.

Cheers,
Mischa
« Last Edit: July 05, 2016, 01:58:14 PM by swich401 »



Offline Mike V.

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Reply #17 on: July 05, 2016, 04:36:45 PM
On C side, you have resistors from the center lug going to 3 and 8 of the tube socket. This is supposed to be 2 and 8.

Cheers,
Mischa

I knew the issue was down there! But couldn't find where, That's the problem of building an amp at late night hours.

That for sure resolved the Bias issue. Thanks!

The final result a clean pure delightful sound!

Crack w/Speedball/HD650/DacMagic-100/

Mainline (on the way)/K702/ProJect Xpression III Classic w/ DL-103R/ Speedbox/Cambridge Audio 651p/


Offline Mike V.

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Reply #18 on: July 05, 2016, 04:39:32 PM
Doc, Paul, Mischa,

Thanks for your help! A tired eye is a dangerous thing lol hopefully all my soldering was clean and well done. Got a clean sound.

Delightful sound!

Crack w/Speedball/HD650/DacMagic-100/

Mainline (on the way)/K702/ProJect Xpression III Classic w/ DL-103R/ Speedbox/Cambridge Audio 651p/


Offline Paul Birkeland

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Reply #19 on: July 06, 2016, 06:16:25 AM
I would also resolder the middle leg of the MJE5731A on the "A" side, as it looks like the flux hasn't flowed out of the joint completely.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man