Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Stereomour => Topic started by: drewh1 on October 24, 2015, 08:57:11 AM

Title: Help - Poor results from Cathode Bypass Mod - user error!
Post by: drewh1 on October 24, 2015, 08:57:11 AM

I installed Mundorf 47 uF's across as described in the thread on this mod.  Soldered caps from t6 - t16 and t10 - t20 as described.  Removed the wires to K on the PCB.

My overall volume seems down about 6 db and my bass response is significantly decreased.  Everything else seems fine. Balance is ok and instruments are where they are supposed to be in soundfield.

Any ideas?

Title: Re: Help - Poor results from Cathode Bypass Mod
Post by: Paul Birkeland on October 24, 2015, 09:15:31 AM

How are the voltages? 

If the voltages are OK, let the amp run overnight, then recheck.

Spending more money on capacitors often times does not improve the performance of an amplifier. 

-PB

Title: Re: Help - Poor results from Cathode Bypass Mod
Post by: drewh1 on October 24, 2015, 11:25:46 AM

Ok - I hear you.  All the other mods I did seemed to make improvements, Should have left great enough alone  :D   Live and learn.

Assuming the voltages are ok, do you think putting the wires to k back in would make a difference?

Title: Re: Help - Poor results from Cathode Bypass Mod
Post by: drewh1 on October 24, 2015, 12:14:39 PM

All voltages check out within 10 or 15%.

The only thing that seemed off was T2 is 240 and T14 is 223.  I don't remember any variations from my original voltage checks.

Title: Re: Help - Poor results from Cathode Bypass Mod
Post by: Paul Birkeland on October 24, 2015, 12:29:14 PM

Quote from: drewh1 on October 24, 2015, 11:25:46 AM

Assuming the voltages are ok, do you think putting the wires to k back in would make a difference?

That would put the other cathode bypass caps back into the circuit.  It might help, but I'd wait a few days on that.

Title: Re: Help - Poor results from Cathode Bypass Mod - resolved
Post by: drewh1 on October 24, 2015, 12:36:57 PM

Thanks for your help Paul - I did figure out the volume issue, it was a wrong setting on J-River that popped up when the computer reset, set to internal volume and started up at 75% of full volume. 

Jury is still out on the bass but i'll give it a few days to settle in.  Mostly things sound really good. I apologize for wasting your time - should have spent more time trouble shooting.