treble caps

[JD0x0]

What type of caps do you use for treble caps? I cant seem to get any 6PS values low enough to put there. Btw im using 330pF for the clean channel and 200pF in the OD section. I have ceramic caps in those values but im worried it will make the high end "scratchy" and "harsh"

[j-po]

Yes, use ceramic 500V.

[Bob-I]

Actually the ceramic grainy tone is a big part of the Dumble tone. Typically I buy several types and several of each, then just listen. I've tried silver mica and IMHO they sounded like ass in my amps but there are examples of Dumbles with SM treble and bright caps so I guess the answer is it depends.

[marcos]

FWIW, my ODS came with a 500 pF silver mica treble cap, which I eventually replaced with a 330 pF, silver mica too. I tried ceramic as well, but preferred the silver mica.I guess it would be best to try both types,really a matter of taste.BTW, I preferred the ceramic type for the bright switch.As usual, trust your ears, Marcos

[glasman]

For what it is worth. HAD was known to use both types (ceramic and silver mica) for the treble cap, just depended on the amp and who he was building it for....

Get one of each and let your ears decide. There are many different temperature coefficents in ceramic, some sound better than others, I like NPOs. YMMV.

Gary

[BobW]

...Get one of each and let your ears decide. There are many different temperature coefficents in ceramic, some sound better than others, I like NPOs. YMMV.

Gary

Very perceptive Gary.
I had an amp that would change / shift the tone after an hour of playing. It was attributed to the temp coefficient of the ceramic I was using. After switching from an X7R to COG(NPO) the problem went away.

[glasman]

...Get one of each and let your ears decide. There are many different temperature coefficents in ceramic, some sound better than others, I like NPOs. YMMV.

Gary

Very perceptive Gary.
I had an amp that would change / shift the tone after an hour of playing. It was attributed to the temp coefficient of the ceramic I was using. After switching from an X7R to COG(NPO) the problem went away.

Gee, I guess in the 3 years of high school electronics, 4 years of college, 40 years of being a ham radio operator and 32 years working in the eletronics busniess I actually learned something .

Really not trying to be a smart a$$.

FWIW, the Y5P (as I remember) also work pretty well. Brands I have had good luck with have been Mallory and Panasonic. Not crazy about Xicons ceramic offering. For SM, CDE is the right choice.

Gary

[ChrisM]

...Get one of each and let your ears decide. There are many different temperature coefficents in ceramic, some sound better than others, I like NPOs. YMMV.

Gary

Very perceptive Gary.
I had an amp that would change / shift the tone after an hour of playing. It was attributed to the temp coefficient of the ceramic I was using. After switching from an X7R to COG(NPO) the problem went away.

Gee, I guess in the 3 years of high school electronics, 4 years of college, 40 years of being a ham radio operator and 32 years working in the eletronics busniess I actually learned something .

Really not trying to be a smart a$$.

FWIW, the Y5P (as I remember) also work pretty well. Brands I have had good luck with have been Mallory and Panasonic. Not crazy about Xicons ceramic offering. For SM, CDE is the right choice.

Gary

Damn your old

jk Gary...


Looked up those caps on Mouser. They don't seem to come in all the values seen in ODS'. What else do you use?

[Funkalicousgroove]

ScottL Turned me on to some great Panasonic X5F caps that seem to maintain pretty well, I've really been into Mica caps lateley though, at least for the treble.

[glasman]

Very perceptive Gary.
I had an amp that would change / shift the tone after an hour of playing. It was attributed to the temp coefficient of the ceramic I was using. After switching from an X7R to COG(NPO) the problem went away.

Gee, I guess in the 3 years of high school electronics, 4 years of college, 40 years of being a ham radio operator and 32 years working in the eletronics busniess I actually learned something .

Really not trying to be a smart a$$.

FWIW, the Y5P (as I remember) also work pretty well. Brands I have had good luck with have been Mallory and Panasonic. Not crazy about Xicons ceramic offering. For SM, CDE is the right choice.

Gary

Damn your old

jk Gary...


Looked up those caps on Mouser. They don't seem to come in all the values seen in ODS'. What else do you use?

Yup older than dirt and twice as dusty. I will be 55 in a few weeks. Got licenced in 1969 as WN6JZS. Today it is KF7XP and I can still copy morse code in my head .

I buy panasonic parts via Digikey. CDE can be had at mouser last time I checked. Sprague also makes a line of SM"s and they are not too bad as well.

[glasman]

ScottL Turned me on to some great Panasonic X5F caps that seem to maintain pretty well, I've really been into Mica caps lateley though, at least for the treble.

Yup, use them as well (cool yellow color), nice and seem to be pretty stable. They also sound good. Shame they don't make a 500 puffer in that series...

[JD0x0]

Thanks everyone, the ceramic caps i got were from tubesandmore.com

labled Y5P theyre 6000V caps, seem pretty generic.

Im not sure if anyone has tried these but i am sure that my ears are very picky on the treble frequencys so i'll try a few different types.

I've heard silver mica caps dont work too well in the preamp section on D style amps, they were described as thin and buzzy when used for the V2 snubbers.

[glasman]

Thanks everyone, the ceramic caps i got were from tubesandmore.com

labled Y5P theyre 6000V caps, seem pretty generic.

Im not sure if anyone has tried these but i am sure that my ears are very picky on the treble frequencys so i'll try a few different types.

I have tried these as well. Not very appealing to my ears.

I've heard silver mica caps dont work too well in the preamp section on D style amps, they were described as thin and buzzy when used for the V2 snubbers.

I only use them as treble caps. either 250, 270, 330 or 390pf ceramics for the snubbers.

[David Root]

How about polystyrene caps, as either treble or plate snubbers? I have poly OD snubbers in my Dumbleized 6SL7 amp.

[BobW]

...Get one of each and let your ears decide. There are many different temperature coefficents in ceramic, some sound better than others, I like NPOs. YMMV.

Gary

Very perceptive Gary.
I had an amp that would change / shift the tone after an hour of playing. It was attributed to the temp coefficient of the ceramic I was using. After switching from an X7R to COG(NPO) the problem went away.

Gee, I guess in the 3 years of high school electronics, 4 years of college, 40 years of being a ham radio operator and 32 years working in the eletronics busniess I actually learned something .

Really not trying to be a smart a$$.

FWIW, the Y5P (as I remember) also work pretty well. Brands I have had good luck with have been Mallory and Panasonic. Not crazy about Xicons ceramic offering. For SM, CDE is the right choice.

Gary

No offense taken Gary, . The ceramics used (manufacturers unkown) were in my parts bin for years (almost 20 years) after Litton closed in New Orleans, they unloaded their inventory in the dumpster. Over the years (for +30 years now, am 57) have I rarely had an amp component have such drastic effect due to temperature coefficient. I was just very suprised that it's not as rare of an occurance as I thought. Cheers