Help me mod my 102 - it's too bright!

[PicknStrum]

So a lot of you helped me out in my 102 build log and I greatly appreciate that. After having the amp for a while and trying a couple different speakers, for me it's just too bright on both the clean and drive channels. I initially had a Texas Heat in the amp which definitely warmed it up a lot. However, I did want to get an EVM12L in there based on so many recommendations. I love the way it breaks-up with the EVM but it made the amp even brighter - although I wasn't completely satisfied with the how bright it was with the Texas Heat anyway.

I did speak to Jelle who sourced NOS resistors for me. His eagle eyes spotted that I had a .01 cap on the bass pot instead of a .001 cap. I quickly put the proper value there but the amp is still pretty bright. He also advised me to try a tantalum or electrolytic as the presence cap since I haven't noticed the presence knob doing anything really. The final thing he advised was for me to try piher trimmers in place of the small ones I currently have in there - he mentioned he didn't know if the small trimmers would affect brightness but it was worth a shot.

So, I have the tantalum presence cap, smaller trimmers, and parts for an HRM on the way from mouser.

I have 3 questions:

1. Curious about your opinions of HRM vs. non-HRM drive channel...
2. What other things should I try to warm up / de-brighten the entire amp? Normal and drive channels included.
3. As I'm writing this, I'm wondering if taking out the bright switch and adding a Deep switch would help (I currently have bright, mid, rock/jazz). The bright switch is way way too bright in my opinion.

For reference, I'm mostly playing at lower volumes, which absolutely has an effect on (perceived?) brightness. Also, I'm not going through a dumblator and don't plan on building one at this point.

Here are some updated pictures if that helps:

IMG_5021.JPG

IMG_5022.JPG

IMG_5023.JPG

IMG_5024.JPG

IMG_5025.JPG

[xtian]

Seems like Jelle suggested things that are esoteric, addressing the last 0.5% of tone. Here's something that goes much more to your point: remove the 500p treble peaker immediately following the Volume pot (look for the 500p||220K pair).

[ijedouglas]

I just finished rebuilding a 102 that I had done a while back and it was also a tad on the bright side. Clip out your master bright cap and see if that helps. My understanding is that it's added to compensate for Robben running a Dumblelator. You can play around with smaller values (stock is 68pf), I've seen on the forum some people like a 20pf or 15pf (ala 124). Think of it as a seasoning You may find its not needed, as is my case. The amp is plenty bright but not harsh

[erwin_ve]

In line with ijedouglas; omit the 68pF on the master and if thats too dark, build up with small steps; 15pF, 33pF, 47pF....
Just use jumper cables to test before soldering.

Erwin

[PicknStrum]

Cool! Thanks for the responses - these are way easier mods than I was expecting. So I'm going to start by cutting the master treble cap - I'll then add back in to taste.

As far as the treble peaker mentioned by Xtian, I understand it has a similar function to the master bright cap. How would cutting the treble peaker affect the amp vs. the master cap. This is just for curiosity / knowledge-sake. I'm going to start with the master bright cap.

[PicknStrum]

Ended up clipping the master cap. I really liked that it didn't seem to change the tone much but took some of the brightness out.

Still felt like the amp was too bright for my tastes so I went ahead and clipped the treble peaker as recommended by Xtian.

The cleans seem perfect to me now. Maybe still just a bit bright on the drive for my tastes. Any recommendations for mods only to the drive channel at this point?

Still wondering if it would make sense to put an HRM stack in there? Opinions?

[talbany]

!02 is a fairly bright amp to begin with..I would replace the Silver mica treble cap to a ceramic. This should help the OD side.
The OD entrance trimer Piher would also help IMO!
Tony

[PicknStrum]

!02 is a fairly bright amp to begin with..I would replace the Silver mica treble cap to a ceramic. This should help the OD side.
The OD entrance trimer Piher would also help IMO!
Tony

Perfect! I've got the Piher on the way already and I'll grab a 390pF ceramic cap. That's the value you're referring to correct? It's the only mica cap I used.

[ijedouglas]

Seems like Jelle suggested things that are esoteric, addressing the last 0.5% of tone. Here's something that goes much more to your point: remove the 500p treble peaker immediately following the Volume pot (look for the 500p||220K pair).

That is an interesting mod. I have never tried it but my understanding is the 500pf contributes to the high-end "sing" these amps produce. Interested to hear what other think?

[talbany]

!02 is a fairly bright amp to begin with..I would replace the Silver mica treble cap to a ceramic. This should help the OD side.
The OD entrance trimer Piher would also help IMO!
Tony

Perfect! I've got the Piher on the way already and I'll grab a 390pF ceramic cap. That's the value you're referring to correct? It's the only mica cap I used.

Correct!!..The ceramics will take some of the spike out of the higher treble frequency's and flatten it a bit..
Of course some of the other things like lowering or removing the bright master. Lets start there and move back
BTW..I don't see your mid pot grounded to the buss bar?

Tony

[ChopSauce]

Seems like Jelle suggested things that are esoteric, addressing the last 0.5% of tone. Here's something that goes much more to your point: remove the 500p treble peaker immediately following the Volume pot (look for the 500p||220K pair).

That is an interesting mod. I have never tried it but my understanding is the 500pf contributes to the high-end "sing" these amps produce. Interested to hear what other think?

I think that - for an unknown reason - no incompetent members seem to be capable of sustaining as many messages as xtian has, on this forum.

Also, I remember that he experiments himself with treble peakers on ODS. Maybe you can find the related post with the Google search feature?

EDIT: I am sorry I haven't caught your question rightly, I think, but at least this is what the OP did and it seems that he was pretty happy with it.

[PicknStrum]

!02 is a fairly bright amp to begin with..I would replace the Silver mica treble cap to a ceramic. This should help the OD side.
The OD entrance trimer Piher would also help IMO!
Tony

Perfect! I've got the Piher on the way already and I'll grab a 390pF ceramic cap. That's the value you're referring to correct? It's the only mica cap I used.

Correct!!..The ceramics will take some of the spike out of the higher treble frequency's and flatten it a bit..
Of course some of the other things like lowering or removing the bright master. Lets start there and move back
BTW..I don't see your mid pot grounded to the buss bar?

Tony

Great! Putting that order in now. The mid pot is grounded to the buss bar on the left lug.

Seems like Jelle suggested things that are esoteric, addressing the last 0.5% of tone. Here's something that goes much more to your point: remove the 500p treble peaker immediately following the Volume pot (look for the 500p||220K pair).

That is an interesting mod. I have never tried it but my understanding is the 500pf contributes to the high-end "sing" these amps produce. Interested to hear what other think?

I think that - for an unknown reason - no incompetent members seem to be capable of sustaining as many messages as xtian has, on this forum.

Also, I remember that he experiments himself with treble peakers on ODS. Maybe you can find the related post with the Google search feature?

EDIT: I am sorry I haven't caught your question rightly, I think, but at least this is what the OP did and it seems that he was pretty happy with it.

Yeah I was happy with the removal of the 500pF cap that Xtian mentioned. It didn't take a huge amount of treble off, after already removing the master bright cap, but it was noticeable. I didn't feel like it compromised the voice of the amp. Just made the treble and mid pots more useable.

[talbany]

Seems like Jelle suggested things that are esoteric, addressing the last 0.5% of tone. Here's something that goes much more to your point: remove the 500p treble peaker immediately following the Volume pot (look for the 500p||220K pair).

That is an interesting mod. I have never tried it but my understanding is the 500pf contributes to the high-end "sing" these amps produce. Interested to hear what other think?

Ian
myself or anyone else I know or have talked too have ever needed to remove that bypass cap? It's normally something I would not recommend doing to try and solve a balance issue..I personally think it's parts selection and or possibly lead dress..This is where I would start anyway..

102 is a fairly bright amp and has been known to surprise quite a few builders.
https://www.youtube.com/watch?v=XUOA_7tInfw

Tony

[ijedouglas]

Seems like Jelle suggested things that are esoteric, addressing the last 0.5% of tone. Here's something that goes much more to your point: remove the 500p treble peaker immediately following the Volume pot (look for the 500p||220K pair).

That is an interesting mod. I have never tried it but my understanding is the 500pf contributes to the high-end "sing" these amps produce. Interested to hear what other think?

Ian
myself or anyone else I know or have talked too have ever needed to remove that bypass cap? It's normally something I would not recommend doing to try and solve a balance issue..I personally think it's parts selection and or possibly lead dress..This is where I would start anyway..

102 is a fairly bright amp and has been known to surprise quite a few builders.
https://www.youtube.com/watch?v=XUOA_7tInfw

Tony

Tony, that's my understanding too. I have never seen one removed in a build or discussed as a tweak. In a discussion with Charlie Wilson, he felt that even lowering that value down to 470pf had an effect on the "sing" of the amp. Thanks for the confirmation.

[talbany]

That is an interesting mod. I have never tried it but my understanding is the 500pf contributes to the high-end "sing" these amps produce. Interested to hear what other think?

Ian
myself or anyone else I know or have talked too have ever needed to remove that bypass cap? It's normally something I would not recommend doing to try and solve a balance issue..I personally think it's parts selection and or possibly lead dress..This is where I would start anyway..

102 is a fairly bright amp and has been known to surprise quite a few builders.
https://www.youtube.com/watch?v=XUOA_7tInfw

Tony

Tony, that's my understanding too. I have never seen one removed in a build or discussed as a tweak. In a discussion with Charlie Wilson, he felt that even lowering that value down to 470pf had an effect on the "sing" of the amp. Thanks for the confirmation.

Sing makes sense
That cap creates a treble boost shelf that begins around the corner frequency of 1.5kHz counteracting the roll off of the Miller capacitance .. Well within the "Sing" range

Tony