Clean channel barks

[morningstar]

I have a Carvin BelAir that has gotten "barky" on the clean channel. Soak is still great and smooths out real well. I don't get what could create such a harsh attack in the clean channel.

Ideas?

thanks

morningstar

[BadgerDave]

I have a Carvin BelAir that has gotten "barky" on the clean channel. Soak is still great and smooths out real well. I don't get what could create such a harsh attack in the clean channel.

Ideas?

thanks

morningstar

Is that a 2 channel amp? My first thought is a failing preamp tube.

[gtone]

I'd guess that the power tubes are done. Try swapping 'em out to see if that makes a difference.

[morningstar]

I'd guess that the power tubes are done. Try swapping 'em out to see if that makes a difference.

Thanks guys. I will try a complete tube swap and see if that helps.

Tommy

[murkat]

if the pre amp tube for chnl clean is too hot, ex. 12ax7, try swapping out for a lighter pre amp tube, ex. 12au7,... etc. some pre amp tubes clean up or breakup more than others. if the power tubes were failing, all would sound terrible no matter what.

[gtone]

if the power tubes were failing, all would sound terrible no matter what.

Not necessarily. Depending on the circuit/tubes, power tubes can die a slow death in such a way that one of the early symptoms can be a barky/sinewy tone through a clean channel or low gain mode. It would typically be accompanied by a general loss in overall power across the board, however. Higher gain modes/channels might otherwise sound fairly normal, other than the loss of output in varying degree. Doesn't necessarily make the whole amp sound like ass, though.

[morningstar]

I found that backing way off the tone controls reduced the bark -- if that tells anyone anything...

I swapped in NOS RCA EL84's. No diff on the clean channel, but they sure do sound nice when kranked.

I swapped in an old NOS gold pin International (Mullard as I gather) 12AT7 in the PI. Nicer.

So into preamp 1 went a used (by me) Sylvania 12AT7. More better.

The dirt channel now is totally freaking awesome. The clean channel is much improved, but could still loosen up and sound better.

How many 12AT7 should I run? I don't want to peel the crispness off the dirt channel. The 12AX7 that remain (3 of them) are Tung-Sol reissues.

At this point I have to buy what I try.

Thanks

morningstar

[murkat]

with lower output pre amps, you are just doing that, lowering the pre ampness to the power stage. If V1 and V3 have been switched, yes V2 will benifit. Its kinda like this....

V1- preamps the guitar signal into~

V2- preamps the tone stack, then into~

V3- preamps the phase inverter circuit that slams into~

Power amp section.

its something like that.

tungsol Re's can be hit/miss

you can find some nice Jan, GE, raytheon's in low power on the cheap, everyone wants the X's which drive up the coin.

[ZR]

.......

its something like that.

tungsol Re's can be hit/miss

you can find some nice Jan, GE, raytheon's in low power on the cheap, everyone wants the X's which drive up the coin.

I have some for sale...

Tube sale

YMMV, but I've never really had a new tube just away blow good vintage stuff. I have more than what's listed but that's all I have that are tested and ready to go.

[morningstar]

Sorry I missed the tube sale until now. Yesterday I snagged a sleeve of Phillips JAN 12AT7

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...e=STRK:MEWNX:IT

I figure whatever I don't use in the Bel Air I can use to sweeten up a V3 or Legacy.

morningstar

[JohnnyB]

Sorry I missed the tube sale until now. Yesterday I snagged a sleeve of Phillips JAN 12AT7

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...e=STRK:MEWNX:IT

I figure whatever I don't use in the Bel Air I can use to sweeten up a V3 or Legacy.

morningstar

I love the Philips JAN preamp tubes from the '80s. I bought three Philips JAN 12AX7WAs for my Top Hat in '98 soon after the JAN NOS supply was released to the market. Creamy, dynamic, clean tight, but relaxed at the same time.

$5 apiece? That's a great score. The 12AX7WAs from that supply have gotten scarcer and more expensive over the years.

[Brewmaster]

A 12AT7 in the PI is a good move in general for the symptoms you are describing and since you already swapped out the el84's and still have the same issue. I would try a 5751 over a 12AT7 in V1.

I love the Philips JAN preamp tubes from the '80s. I bought three Philips JAN 12AX7WAs for my Top Hat in '98 soon after the JAN NOS supply was released to the market. Creamy, dynamic, clean tight, but relaxed at the same time.

$5 apiece? That's a great score. The 12AX7WAs from that supply have gotten scarcer and more expensive over the years.

I remember paying $15.00 a piece for a bunch of these back around 7-8 years ago. They are around $50.00 a piece now. $5.00 a piece for Jan Philips 12AT7's and you weren't wearing a mask?

[morningstar]

No mask, just my hamernut eBay alias. Prices on eBay are goofy. I just grabbed what I knew to be a good price and let the high priced stuff go to the rich people.

The JAN tubes have partially cut into the barkiness.

I also put in a set of NOS RCA EL84's. The power amp tubes had zero effect.

Any other ideas?

Thanks

morningstar

[RobB]

Thommy! Email me: flyingV AT sbc GLOBAL dot NET. I can't seem to PM ya...