Preamp Tubes Suggestions For 6505+ Head

[Charvel1975]

Hey guys wanted some input from 6505+ head owners on preamp tubes in my 6505+ head I just picked up last week. The previous owner put the stock tubes back in about 2 years ago and they have some play time on them and he recommended replacing all of the tubes so I just got a quad of EH 6L6's off Lord Toneking, thanks again dude and I was getting ready to take the preamp tubes out of my Tverb and put them in the Peavey cause it's humming and crackling and sounds like I have a bad pre tube but I just found these tubes in a basket I had downstairs:

1 Electro-Harmonix 12ax7 Made In Russia 0011

1 Mesa 12ax7A Russian 2

2 Groove Tubes 12ax7C's

6 Groove Tubes GT12ax7R's

So now it looks like I won't need to take the preamp tubes outta the mesa, out of those 10 preamp tubes I listed could you recommend what positions and how to tell what position on my 6505+ head I should try any of those preamp tubes listed above, I have no idea which position is which cause it's not listed in Peavey's manual online for it? Thanks!

 

[Charvel1975]

Ok so I wiped down the head with a damp rag to get all the dust, etc. off the headshell and front control plate and swapped the old preamp tubes out, haven't swapped out the Ruby 6L6GCM-STR's for the EH's yet, wanted to see how it sounded with just the preamp tube change and see if it resolved all the humming and crackling noises. I even went from running 4 Ohms to 16 Ohms to see how that would sound, here's what originally was in the preamp looking at the back of the head going from right to left: 4 JJ 12ax7's and 2 Sovtek 12ax7LPS's, I took all those out and put in again going from right to left: Groove Tubes 12ax7C, Electro-Harmonix 12ax7 Made IN Russia 0011, Groove Tubes 12ax7C, Mesa 12ax7A Russian2, and the last 2 preamp slots put in 2 other Sovtek 12ax7LPS's I found laying around. Let the amp warm up, played around with both channels with post around 1, noticed it was a lot louder on 1, sounded killer and then after about 25 minutes of playing all the humming and crackling noises came back so I immediately switched it back to the rhythm channel put it on standby for a couple seconds and then turned the amp off, I don't get it?? Anyone care to chime in here

 

[5150clone]

Check with Laura at Valve queen. She picked mine out and it was perfect. ...

 

[Rob R]

STAY AWAY FROM EURO TUBES, TAds work great!!

 

[D-Rock]

Maybe patch the effects loop with a jumper cable. See what that does.

 

[rrobertson]

You probably have a bad power tube...why not go ahead and change them if you have new ones?

 

[Lord Toneking]

You probably have a bad power tube...why not go ahead and change them if you have new ones?

This^^^ You know the power tubes I gave you are practically brand new

If it still is acting up swap pre tubes one at a time till you find the culprit

 

[Charvel1975]

You probably have a bad power tube...why not go ahead and change them if you have new ones?

This^^^ You know the power tubes I gave you are practically brand new

If it still is acting up swap pre tubes one at a time till you find the culprit

Thats the plan, for some reason after I did the preamp tube swap the amp was a lot louder on 1 on either channel but when engaging the crunch on the rhythm channel there was the normal volume jump. Lord Toneking when I go to put those EH 6L6's in, the bias control is already up like a quarter of the way should I turn it up to half then put in the EH's then turn the amp on and let it warm up for 5 minutes? I was also looking around online to see what other 6505+ owners were using in their preamp and I came across this online:

V4 - Sovtek 12AX7LPS
V3 - Tung-Sol 12AX7
V5 - Sino (Chinese) 12AX7A or shuguang (I have heard you should not put Russian made tubes here)
V2 - Tung-Sol 12AX7
V1 - JAN-Philip 5751
V6 - Tung-Sol 12AX7

 

[Lord Toneking]

I think youre putting way too much thought into this. No pre tube is going to hurt anything in there, it's all a matter of taste/flavor tonally

I put all Ruby pres in mine and it sounds fine. There is no correct or certain tube you need to use

get the amp to function properly by making sure ALL the tubes are good. Once you do that then you can start trying different tubes for different tones. As of right now it seems youre still troubleshooting

 

[Charvel1975]

I think youre putting way too much thought into this. No pre tube is going to hurt anything in there, it's all a matter of taste/flavor tonally

I put all Ruby pres in mine and it sounds fine. There is no correct or certain tube you need to use

get the amp to function properly by making sure ALL the tubes are good. Once you do that then you can start trying different tubes for different tones. As of right now it seems youre still troubleshooting

Gotcha! I'll put in the EH6L6's 1st and then see what happens, should I just leave that bias control where it's at for now and not bother adjusting it when I put in the EH's?

 

[Charvel1975]

I ordered the preamp cover plate, back panel protective cover, power cord hooks and screws thru peavey earlier this week too, waiting for those to get here

 

[Lord Toneking]

I think youre putting way too much thought into this. No pre tube is going to hurt anything in there, it's all a matter of taste/flavor tonally

I put all Ruby pres in mine and it sounds fine. There is no correct or certain tube you need to use

get the amp to function properly by making sure ALL the tubes are good. Once you do that then you can start trying different tubes for different tones. As of right now it seems youre still troubleshooting

Gotcha! I'll put in the EH6L6's 1st and then see what happens, should I just leave that bias control where it's at for now and not bother adjusting it when I put in the EH's?

Yes, that bias control will always keep it in the safe zone no matter how high you set it.

Use your ears

 

[Charvel1975]

I think youre putting way too much thought into this. No pre tube is going to hurt anything in there, it's all a matter of taste/flavor tonally

I put all Ruby pres in mine and it sounds fine. There is no correct or certain tube you need to use

get the amp to function properly by making sure ALL the tubes are good. Once you do that then you can start trying different tubes for different tones. As of right now it seems youre still troubleshooting

Gotcha! I'll put in the EH6L6's 1st and then see what happens, should I just leave that bias control where it's at for now and not bother adjusting it when I put in the EH's?

Yes, that bias control will always keep it in the safe zone no matter how high you set it.

Use your ears

Put the EH6L6's in, turned the bias control to half, let it warm up, turned it on and all the humming & crackling noises are still there, seems like it lost some punch and high end too??

 

[Charvel1975]

Do I necessarily have to have 2 of the Sovtek 12ax7LPS's in the preamp? Would it hurt to swap out the pre's again and put the 6 Groove Tubes GT12ax7R's in?

 

[sjk]

As was stated you are way overthinking this, just start swapping preamp tubes, experiment

 

[Inquisitor]

Yeah, I'd try out a couple different combos. I bought some EHs 12AX7 thinking they would be vastly better than the Chinese made tubes I got the amp with. Turns out that I like the Chinese made tubes in the 2nd and 3rd positions, which totally blew my mind. More noise when im not playing, but creamier distortion and not as harshly bright. Pretty cool lesson learned

 

[Charvel1975]

Yeah, I'd try out a couple different combos. I bought some EHs 12AX7 thinking they would be vastly better than the Chinese made tubes I got the amp with. Turns out that I like the Chinese made tubes in the 2nd and 3rd positions, which totally blew my mind. More noise when im not playing, but creamier distortion and not as harshly bright. Pretty cool lesson learned

I did put the 2 GT12ax7C's in the 2nd and 3rd positions, I'm assuming the C at the end means Chinese?

 

[Charvel1975]

I've done more preamp tube swapping and after letting the amp warm up after tube swaps it's still humming really bad and the humming, crackling etc is happening on either channel on the Post volume controls from 0 to about a hair above 2 then it stops but then after a while comes back? I think the front panel pots need shot with some electronic contact cleaner

 

[Inquisitor]

I ended up switching out the pots. Peavey uses the cheapest parts known to mankind and ant kind. And China. Obviously the ones that matter, no need in switching out all of them unless you do funky eq while playing. The 5150 is a notoriously noisy amp, you grow used to it haha. The 6505 is supposed to be cleaner, but the way it sounds is pots to me.

 

[Anonymous]

my recommendation is shuguang 12ax7b
http://www.vacuumtubesupplies.com/Vacuu ... e-p59.html

check your phase inverter tube the pretube closest to the power tubes.

follow the flowchart on FJA website.

i've also experienced some weird oscillating noises that stem from close solder traces/bad solder traces on the preamp board....but, if you're not sure what you're doing in an amp, just take it to a tech.