Bright Cap on Master Volume?

[Structo]

What say you guys?

Do you have a 15pf cap or other value on your master volume on your D clone?
Or on the preamp volume pot?

I see this on some layouts and schematics and was wondering about that mod.

[ayan]

What say you guys?

Do you have a 15pf cap or other value on your master volume on your D clone?
Or on the preamp volume pot?

I see this on some layouts and schematics and was wondering about that mod.

In non HRM amps with a single, overall master volume, I recommend using a 30pF cap. It will give the cleans a bit of shimmer without making the OD sound too harsh. I do have a treble bleed at the output of the OD, perhaps without that even a 30pF would be too much. For the clean sound, a 47pF would be "better," and that's the reason you see mostly that in HRM amps where there are completely independent master volumes. I have heard an amp with a 68pF on the clean master and I still prefer 47pF.

Gil

[glasman]

I go with Gil on this one, I usually put a 47pf to sweeten the tone. I have also used 68pf and it will work with some tone stack topographies.

Gary

BTW - GIL your Oh-Oh came to pass .

[Structo]

I should clarify that this is on my D'Lite amp that has been pretty heavily modded towards Dumble specs, well as much as I can on a 50 watt amp.

Is it true that at lower volumes the brightness from the cap will be apparent but at louder volumes it won't have as much effect?
Sort of like a treble bleed on a guitar volume control?

[talbany]

Is it true that at lower volumes the brightness from the cap will be apparent but at louder volumes it won't have as much effect?
Sort of like a treble bleed on a guitar volume control?

That is correct!!!

Bright caps are a total taste part for me!! I file them in the tweak category..I could care less what Dumble used.... In order to get the right value for the cap you should hook up the cab you want to use with the amp and guitar you favor.... Set the amp at the general volume level you use then tack in a couple caps..Just cause someone else used it doesn't make it right for your setup...



Tony VVT

[ayan]

I should clarify that this is on my D'Lite amp that has been pretty heavily modded towards Dumble specs, well as much as I can on a 50 watt amp.

Is it true that at lower volumes the brightness from the cap will be apparent but at louder volumes it won't have as much effect?
Sort of like a treble bleed on a guitar volume control?

For those of us using an external D-lator device, the settings on the amp never chnage, regardless of what volume is required -- the D-lator return becomes the rig's master volume. So, pick a cap that you like and find the sweet spot on the master volume for that cap... and then forget about tweaking that ever again.

Gil

[dogears]

Yep. Agree! I use a 47pf as well. I'll add that I have specific loop cables that measure between 150pf and 180pf on both the send and returns. It is a system.

I should clarify that this is on my D'Lite amp that has been pretty heavily modded towards Dumble specs, well as much as I can on a 50 watt amp.

Is it true that at lower volumes the brightness from the cap will be apparent but at louder volumes it won't have as much effect?
Sort of like a treble bleed on a guitar volume control?

For those of us using an external D-lator device, the settings on the amp never chnage, regardless of what volume is required -- the D-lator return becomes the rig's master volume. So, pick a cap that you like and find the sweet spot on the master volume for that cap... and then forget about tweaking that ever again.

Gil

[talbany]

F

or those of us using an external D-lator device, the settings on the amp never chnage, regardless of what volume is required -- the D-lator return becomes the rig's master volume. So, pick a cap that you like and find the sweet spot on the master volume for that cap... and then forget about tweaking that ever again.[/quote

Gil


Just Curious what do you run your master at on a gig with the lator...




Tony VVT

[ayan]

F

or those of us using an external D-lator device, the settings on the amp never chnage, regardless of what volume is required -- the D-lator return becomes the rig's master volume. So, pick a cap that you like and find the sweet spot on the master volume for that cap... and then forget about tweaking that ever again.[/quote

Gil

Just Curious what do you run your master at on a gig with the lator...


Tony VVT

Well, Tony, let me offer a clarification before typing the answer to your question. Basicallly, no two amps of mine are alike in that there are small variations here and there (pot tolerances, different tubes, Lord knows what, etc.) such that the "visual settings" to achieve a similar sound are not the same. So, remember, "this pot" set on 4 may be equivalent to "that other" pot set in 5, even if they are the same brand and purchased from the same vendor.

For my Blues Master amp, I run the preamp volume at about 1+ o'clock and the clean master at about 10+ o'clock with a 47pF brightness cap on it. The sound is pretty chimey that way, the amp is very loud, and I can get the clean channel to downright crunch with the PAB on. For my non HRM amps, I run the preamp volume between 11 and 12 o'clock and the master (it's an overall master in this case) at 1 o'clock with a 30pF on it. Because of the cap size and the master volume setting, the sound is not nearly as chimey and it has a midrange focus to it because of the voicing of the amp. The clean channel is very clean, hard to make it crunch with the PAB on, and the overall volume of the rig is comparable to the BM with the settings described, but probably not as loud. I have two non HRM amps, the settings quoted are for my gigging amp... in the other amp I can get the same volume with the master set lower (around 12 o'clock) and the sound is a little chimier.

Hope this answers your question without adding confusion to the conversation.

Gil

[talbany]

Well, Tony, let me offer a clarification before typing the answer to your question. Smile Basicallly, no two amps of mine are alike in that there are small variations here and there (pot tolerances, different tubes, Lord knows what, etc.) such that the "visual settings" to achieve a similar sound are not the same. So, remember, "this pot" set on 4 may be equivalent to "that other" pot set in 5, even if they are the same brand and purchased from the same vendor.

For my Blues Master amp, I run the preamp volume at about 1+ o'clock and the clean master at about 10+ o'clock with a 47pF brightness cap on it. The sound is pretty chimey that way, the amp is very loud, and I can get the clean channel to downright crunch with the PAB on. For my non HRM amps, I run the preamp volume between 11 and 12 o'clock and the master (it's an overall master in this case) at 1 o'clock with a 30pF on it. Because of the cap size and the master volume setting, the sound is not nearly as chimey and it has a midrange focus to it because of the voicing of the amp. The clean channel is very clean, hard to make it crunch with the PAB on, and the overall volume of the rig is comparable to the BM with the settings described, but probably not as loud. I have two non HRM amps, the settings quoted are for my gigging amp... in the other amp I can get the same volume with the master set lower (around 12 o'clock) and the sound is a little chimier.

Hope this answers your question without adding confusion to the conversation. Smile

Gil

Gil
Thanks for the detailed response and clarification...I am always interested in how people set there rigs up.... Especially one who knows these amps..




Tony VVT

[Structo]

It also matters if we're talking 100 watt (4 holers) vs 50 watt amps, right?

I know the 100 watt amp isn't twice as loud but has a character all it's own in the tone department when compared to a 50 watter.

I installed the 47pf on my master yesterday. I also changed a couple wires to promote better lead dressing, but now I have a hell of a 60 Hz hum in the OD that I didn't notice before. The fun never stops!

[Structo]

I was messing around with a tone stack calculator and it appears that the bigger the cap is the bigger boost to the high frequencies?
I see it drops back the knee a bit.

Is this valid for the bright cap on the master volume or does it act differently?

So I used the Duncan Tone Stack Calculator.

This screen shot is of a 47pf cap and a 100pf cap, both with the treble pot dimed to show the most difference.

So what I'm getting at, is what the affect of going larger with the bright cap is.

[butwhatif]

I think this cap is a very fine tune item, depending on the speaker, too big can really obliterate the sweet fat distortion sound, yet the clean sound needs something to top it off. I think most guys play with the master under 5 or so, and that's where this cap has a role in the sound. I tried many values, and in one amp settled on 28 pf after gigging the amp a few times. I'll use the presence if i need more. I also have the treble bleed on a pull switch, as some rooms are better without it. I also have in mine a 'partially on' bright switch on the preamp volume-a cap in series w/ a resistor-which works for the clean sound, but is hardly noticeable in distortion, although i never use the bright switch full on.

[Structo]

Thanks, I hear you on the different acoustics of venues.

Yesterday I added more filtering by piggy backing two 100uf caps on top of the existing 100uf caps in the power supply.
So I turn it back on expecting it to cure the humming.......no dice.

So last night I was messing around with the amp and found that the source of the hum was a homemade Dyna/Ross compressor pedal I built.

For some reason when that was in the chain into the front of the amp it was inducing a lot of hum.
I may have a ground loop or something going on with the One Spot pedal supply or possibly a grounding issue within the pedal itself.

After I took that pedal out of the chain, the amp quieted back to the normal hum and hiss that it always has had, which really isn't very audible at all.

Anybody ever try a small variable capacitor (trimmer cap) in the bright cap range?