c30 tube replacement

This forum is for talking about all kinds of Peavey guitar amplifiers.
Post Reply
labradchord
Member
Posts: 13
Joined: Mon Jul 08, 2013 7:22 pm

c30 tube replacement

Post by labradchord » Tue Jan 14, 2014 9:28 am

Hey I need some help replacing tube on a c30...

Since c30 is supposed to be fixed bias, I figured I can change the tubes myself.

I replaced them according to the tutorial, but when I turn on the amp, there is no sound at all.

Any ideas?

Classic30inCincy
Member
Posts: 31315
Joined: Fri Sep 12, 2008 3:10 pm
Location: The Mountain Retreat [Cincinnati Ohio]

Re: c30 tube replacement

Post by Classic30inCincy » Tue Jan 14, 2014 9:49 am

Tubes possibly not fully seated in power tube sockets.

With the C30 all tubes must be functional or none are functional.

PAF Classic Series Tube Kit.......Created By Classic30inCincy
Majic Mojo Tradename..........Created By Classic30inCincy
Graduate Of Joe Friday / Dragnet School Of Correspondence
Doctorate Degree Diplomacy From Royal Order Possum Lodge

labradchord
Member
Posts: 13
Joined: Mon Jul 08, 2013 7:22 pm

Re: c30 tube replacement

Post by labradchord » Tue Jan 14, 2014 10:08 am

it looks like they're seated just fine, maybe one of them doesn't work, but I doubt it, they should be tested.

Ok, just to make sure this is not a bias problem. I replaced sovtek el84 power tubes with JJ EL84's and the electro harmonix and 2x sovtek 12ax7 with TungSol 12AX7, JJ ECC803S and Sovtek 12AX7LPS. It should work, right?

Classic30inCincy
Member
Posts: 31315
Joined: Fri Sep 12, 2008 3:10 pm
Location: The Mountain Retreat [Cincinnati Ohio]

Re: c30 tube replacement

Post by Classic30inCincy » Tue Jan 14, 2014 10:38 am

Yes it should work.

Was the amp working properly before tube change ?

Are the tubes lighting up ? ?

New tubes can arrive with shipping damage.

Power tubes AND Position V3 Phase Inverter must be fully seated.

Amp might have a blown fuse on the circuit board.

No bias adjustments needed or required.......

Plug & Play

Recommend acquiring electronic spray cleaner.

Remove all tubes, clean sockets, re-install tubes.

PAF Classic Series Tube Kit.......Created By Classic30inCincy
Majic Mojo Tradename..........Created By Classic30inCincy
Graduate Of Joe Friday / Dragnet School Of Correspondence
Doctorate Degree Diplomacy From Royal Order Possum Lodge

labradchord
Member
Posts: 13
Joined: Mon Jul 08, 2013 7:22 pm

Re: c30 tube replacement

Post by labradchord » Tue Jan 14, 2014 11:16 am

Ok, so I turned it on to check the tubes and now is working fine. I just moved it around a bit, so it could be that a tube is borderline properly seated. that's the only idea on why it wouldn't work the first time ?

Classic30inCincy
Member
Posts: 31315
Joined: Fri Sep 12, 2008 3:10 pm
Location: The Mountain Retreat [Cincinnati Ohio]

Re: c30 tube replacement

Post by Classic30inCincy » Tue Jan 14, 2014 1:20 pm

Tube / Tubes not fully seated.

Good example regarding cleaning sockets prior to installing new tubes.

PAF Classic Series Tube Kit.......Created By Classic30inCincy
Majic Mojo Tradename..........Created By Classic30inCincy
Graduate Of Joe Friday / Dragnet School Of Correspondence
Doctorate Degree Diplomacy From Royal Order Possum Lodge

labradchord
Member
Posts: 13
Joined: Mon Jul 08, 2013 7:22 pm

Re: c30 tube replacement

Post by labradchord » Tue Jan 14, 2014 4:34 pm

how exactly do i clean the sockets?

Classic30inCincy
Member
Posts: 31315
Joined: Fri Sep 12, 2008 3:10 pm
Location: The Mountain Retreat [Cincinnati Ohio]

Re: c30 tube replacement

Post by Classic30inCincy » Tue Jan 14, 2014 4:47 pm

Road Trip To Radio Shack......

Acquire Electronic Spray Cleaner (Radio Shack Brand, Etc)

Spray Cleaner On Pins Of An Older Tube

Work Pins In & Out Of Socket (To Exercise Socket)

ALWAYS Work With Amp Unplugged

Consider Multiple Cleanings

Allow Sockets To Dry Prior To Installing Tubes

PAF Classic Series Tube Kit.......Created By Classic30inCincy
Majic Mojo Tradename..........Created By Classic30inCincy
Graduate Of Joe Friday / Dragnet School Of Correspondence
Doctorate Degree Diplomacy From Royal Order Possum Lodge

kenhan
New Member
Posts: 6
Joined: Sat May 03, 2014 4:33 pm

Re: c30 tube replacement

Post by kenhan » Mon Jul 24, 2017 2:44 pm

I am resurrecting an old thread.

I have a Classic 30 that I bought new from Sweetwater in 2014. It seems to have developed quite a hissy noise when in the drive channel, and more recently a very high pitched ringing note regardless of what channel I am in. That high pitched noise temporarily goes away when I tap on the first power tube. So I'm thinking I need to change out the tubes.

I saw Cincy's full recommended tube replacement somewhere, although I can't seem to find it now. My question is more about the first preamp tube. I read somewhere that changing the first preamp tube to either AT or AY variety instead of the usual AX type can change the amp to offer a better clean sound. I most play jazz and use the clean channel, although I like to put on some gain every now and then either by switching he amp channel or with a pedal. What would changing the first tube to either AT or AY exactly do? Any particular recommendations for a AT or AY tube? Thanks!

ScottMarlowe
Member
Posts: 1475
Joined: Sat Jun 07, 2014 6:23 am
Location: Denver, CO

Re: c30 tube replacement

Post by ScottMarlowe » Mon Jul 24, 2017 3:11 pm

I recommend 5751 tubes, but even different 12AX7s can make a big difference in tone etc.

Classic54
Member
Posts: 152
Joined: Tue Aug 14, 2012 12:46 pm

Re: c30 tube replacement

Post by Classic54 » Mon Jul 24, 2017 4:39 pm

Do not use a 12AT7 in a gain stage unless the circuit is designed for it and the C30 is not. 12AT7 (and 12AU7) tubes are designed to drive current, not voltage gain, and are used mostly as driver tubes for reverb and phase inverters in Fender amps. They are pin compatible and will work but tone will not be good.

For gain stages use 12AX7, 12AY7 and 5751.

ScottMarlowe
Member
Posts: 1475
Joined: Sat Jun 07, 2014 6:23 am
Location: Denver, CO

Re: c30 tube replacement

Post by ScottMarlowe » Mon Jul 24, 2017 4:45 pm

Classic54 wrote:Do not use a 12AT7 in a gain stage unless the circuit is designed for it and the C30 is not. 12AT7 (and 12AU7) tubes are designed to drive current, not voltage gain, and are used mostly as driver tubes for reverb and phase inverters in Fender amps. They are pin compatible and will work but tone will not be good.

For gain stages use 12AX7, 12AY7 and 5751.
TBF some people like that awful grindy tone a 12AT7 gives them (I don't, I'm with you on this one).

Also don't forget 7025s as well. Mostly nowadays they're just re-badged 12AX7s though.

Post Reply