Hi guys! I've been breaking in my OTS now for about a month and continue to be impressed by the variety of tones it can achieve. Today I found something that I hope I can correct. The low end sounds a little loose when playing at anything above moderately loud volumes. The OTS is stock as received from Nik, no mods done yet.

Speaker cabinet details:
I'm using a repro Fender Bandmaster piggyback style 2 x 12 cab that is loaded with Celestions...one Vintage 30 and one G12H Heritage. They are both 8 ohms and are wired to operate at 4 ohms...this is because I have a 64 Fender Bandmaster that pairs up with the cab which, as you all already probably know, runs at 4. The combination of these two speakers sounds fantastic with both the Fender and the OTS. I know the problem is not the speakers because the Bandmaster sounds very tight and focused when cranked. 

OTS settings are as follows:
Volume: 5
Bright: Down
Deep: Down
Rock/Jazz: Rock
Treble: 5
Mid: 5
Bass: 3
OD Channel Level: 5
Ratio: 3
Master: 3
Presence: 5

Just for a frame of reference...these setting nailed Robben Ford's 'Rugged Road' sound....

I noticed that when I switched to the Jazz setting, the low end kind of tightened up but the overall tone wasn't the same. I tried to adjust some settings but it lost some sustain which makes sense after reading some of the posts on that subject. Anyway, the overall sound is great but it would be nice to have the low end tightened up a bit. 

Do you guys think if I install 2 X additional 47uF, 350V caps in parallel to the 2 X 100uF, 450V from factory (Zucker Mod) that it would solve this problem? 

Maybe a mod to the Rock/Jazz circuit?

if you bass weakness is a problem in BOTH clean and OD - then look a the powersupply caps as you've suggested.

If it only happens in OD, then you should try the "Ayan Gil mod" from ampgarage.com.
....install a 10m resistor (input to ground)/ 47 nF (input to on the input of the OD just before the 220k resistor) this will trim off a little low end and make the tone less wobblely in OD

Just for info, the amp has the folloving values

3,3k / 5uf is 10hz cut off frequency
2,2k / 5uf is 14 Hz cut off frequency

You are suggesting

3,3k / 2,2 uF is 22 hz cut off freq
2,2 / 2,2 uF is 33 hz cut off freq

OR

3,3k / 1 uF is 48 hz cut off freq
2,2 / 1 uF is 72 hz cut off freq

Just to get the record straight, what Fullerplast is suggesting has the exact same effect as the suggested Gill Ayan mod.

Anyway
If the problem is both in clean and OD mode try recuding the cathode values on V1.
If only in OD mode then do it only on V2

[quote/]
Just to confirm...the cathode bypass caps are connected to V1 and V2 via pins 8 correct? My OTS should be the newer version with the Zucker mods so they both should be 4.7uF caps. I will check that tonight. [/quote]

yes, pin8 and pin3
[quote/]
By "2,2k and 3,3k" are you referring to the resistors installed in parallel with the  bypass caps on both V1 and V2? [/quote]

yes, pin3 and pin 8 on V1 AND pin3 and pin 8 on V2

The parts you have listed are all fine, but you still need to answer the basic question: Is your bass issue evident in both clean and OD mode ??

yes, pin8 and pin3

[/quote]
By "2,2k and 3,3k" are you referring to the resistors installed in parallel with the  bypass caps on both V1 and V2?
[/quote]

yes, pin3 and pin 8 on V1 AND pin3 and pin 8 on V2

The parts you have listed are all fine, but you still need to answer the basic question: Is your bass issue evident in both clean and OD mode ??
[/quote]

I will check that out tonight if my wife and kids give me a chance...LOL!

I did not test the clean channel but will and will update this post.

Thanks again!

I am definitely a newb....no shame in admitting it...

I tried looking for the details on the Gil Ayan mod in ampgarage.com but am not having much luck...a lot of posts to read through. I will keep looking...

Thanks again guys!

Here Ya go: http://ampgarage.com/forum/viewtopic.php?t=5888    it's quite easy

That's it....