Age Old Problem of TOOO Bright Super Reverb

[old guy]

Love my Super ... '65 ReIssue ... but I just can't take it no more. Yes, I've done a million tube swaps; yes I've swapped out numerous speakers and still, I have to play my humbuckers on middle or neck positions. I don't dare feed my Tele through it. The best combination of parts so far has been a 5R4GBY rectifier, a pair of Svetlana PTs, a CV4004 PI, 3 CV4004 Mullard preamp tubes a Tung Sol 12AU7 in reverb slot with channel one tube pulled. I run her on only 2 of the Italian P10R Jensens and never play louder than 3 on the dial. With my primary guitar - ES-335 - the sustain, the power, the tone is superb - if I can avoid hitting the high E string and sometimes the B (depending on where on the neck I am).

Is there not a simple internal fix like modifying a treble cap or something? Before I go snipping and clipping and soldering, is it true there is something attached to the channel volume control that acts like a treble boost all day and if removed, brings down the high end to usable levels??? Or is this a fairy tale?

[Jazz P Bass]

The only item that comes to mind, as a quick fix, is the mixer resistor capacitor.(C13)
Remove it.

Super Reverb RI Mixing Resistor Cap.pdf

[g1]

is it true there is something attached to the channel volume control that acts like a treble boost all day and if removed, brings down the high end to usable levels??? Or is this a fairy tale?

That would be the "bright" cap, which in the super is switchable. I assume you already have it turned off .

[Leo_Gnardo]

Another handy place to do some treble adjustment is with the contour resistors on each tone stack. Standard value for contour R is 100k. You can probably get to these without having to pull the circuit board out, and tack another resistor in parallel. Somewhere in the range 68K to 220K will get you noticeably more mids/lows and less highs. The lower value, the "darker" the tone.

On the vibrato channel, removing the 10 pF cap that's in parallel with 3M3 at reverb/dry mix node will also knock off some sizzle. There's no similar fix for the normal channel. Drat.

[Tom Phillips]

Old Guy,

You didn't mention the tone control settings you are using so I'm just checking that you have investigated the whole range of settings. I bring this up because I have found many players who set the tone controls (and volume) to the numbers they traditionally use and then evaluate the sound of an amp with those settings to the sound of other amps with the same settings. Anyway...I just want to be sure. Is there any setting of the tone controls that will give you the tone response that you like?

Also, let's explicitly verify the following:
1) The amp is stock except for the tube swapping that you described.
2) The bright switch is indeed in the OFF position. (Switch down)
3) The bright switch is working. I.e. you can hear the high frequency tone change when you change the bright switch position thus verifying that it's not stuck in the bright mode. (Shorted switch or other circuit path)
4) Do both channels of the amp have the same "problem."

If all this is OK then my next step would be to look at the component values installed in the circuit board and make sure that they are correct. I have found many cases where that amp had incorrect parts installed when it left the factory. Did you purchase it new?
My first approach is to make sure that the amp is operating properly before we make any mods.

Please let us know the answers to the above questions.

Cheers,
Tom

[J M Fahey]

Sell it. Period.

It's useless for you and no tweaking will turn an orange into a pear.

[Richard]

It's so frustrating to have a tone that is so close to what you want but still not quite there. Is there a popular song with a similar tone to the one that you are seeking? Have you tried different speakers? Have you got the sound you wanted out of another amp? The 10" speakers will tend to have more high end and less bass than 12's or 15's and the 4x10 configuration can be a bit beamy. On my Super installing a 5751 (slightly lower gain in V1 allowed me to bump up the volume enough to reduce the effect of the bright switch although you have probably tried that.

I think trying some different speakers (good thing you are only using 2 as it can get expensive) might be fruitful. Adjusting pickups, lower value controls in the guitar, maybe even different strings or instrument cable could also help. Some non true bypass pedals do a good job of knocking off high end even when switched off.

All the suggestions of others will likely help but I prefer to stay out of the amp when possible, I have a phobia about soldering on pcb's.

[olddawg]

A couple of things...SRs are notoriously loud and bright. Like an ice pick with some guitars. As was said before. You can't make a cat a dog. You might be better served selling the amp and moving on. That said... Do you use the tone control on your guitar at all? You might be surprised how many people simply don't. It's amazing what a few degrees of treble cut with a tone control can accomplish. Another solution might be a stomp box or rack eq.

[Chris - CMW amps]

some small things will help:
- mounting the 1k5 gridstoppers and the 470 ohms screengridstoppers ON the output-tube-sockets
- lowering the bright-cap-value from 120pF to (let's say) 47pF
- adding a cap between both plates from V6 (phase-inverter); let's say 100pF or less
- check the biasing (try to get around 60% of Pa max)
- JJ preamp-tubes
big things:
- SPEAKERS! I really like 80s Celestion 10L35s in SRs, warm but still enough detail and a ballsy low-end.

hope this helps