#1
I have a 6505 head i bought used through guitar center

i've had it for almost 2 months now, and everything's great except one thing

sometimes (it's happened two times) when i'm playing, i'll just lose all low end and it gets really fizzy and small/thin sounding. i'll turn it off for a while and when i plug back in it's fine

this is the first tube head i've owned, could this be a serious problem?
1997 Ibanez RG550 w/ EMG 81 bridge - C standard
PEAVEY 6505
Mesa Rectifier slant 4x12
#2
Have you replaced the tubes at all since you bought it?
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#3
Quote by lemurflames
Have you replaced the tubes at all since you bought it?



i have not

once i get some more money together i plan to do that along with getting an od808
1997 Ibanez RG550 w/ EMG 81 bridge - C standard
PEAVEY 6505
Mesa Rectifier slant 4x12
#4
t00bez!!

p.s. tubes are pretty cheap.
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#5
i have been reccommended JJs for the preamp, what about the power amp?
1997 Ibanez RG550 w/ EMG 81 bridge - C standard
PEAVEY 6505
Mesa Rectifier slant 4x12
#6
Just run over to GC and have em give you some matching Mesa tubes and be done with it. Simple and quick. I'm not sure but I heard they were using JJ's right now.
Guitars
- Strandberg OS6, Strandberg CL7, Gibson LP Studio, S570DXQM, RG7421, Mayer Strat, Partscaster

Amps
- TC-50, Mark Five:25, Invective (soon), Vypyr 60
#7
Quote by BoneAndDream
i have been reccommended JJs for the preamp, what about the power amp?

JJs all the way.
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#8
What channel are you playing on and does the volume change when this problem happens?

My guess here is a bad preamp tube.


To start troubleshooting I would simply remove and reinsert all the preamp tubes. If you have contact cleaner on hand spray that in the socket.

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Peavey 6505+ w/ Avatar 212 cab
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#9
Quote by Tremolo Bum
What channel are you playing on and does the volume change when this problem happens?

My guess here is a bad preamp tube.


To start troubleshooting I would simply remove and reinsert all the preamp tubes. If you have contact cleaner on hand spray that in the socket.



i was playing on the lead channel

i couldnt really tell if i actually lost volume or i just perceived loss of volume because of all the low end gone
1997 Ibanez RG550 w/ EMG 81 bridge - C standard
PEAVEY 6505
Mesa Rectifier slant 4x12
#10
Quote by BoneAndDream
i have been reccommended JJs for the preamp, what about the power amp?

If you have a tight budget, JJ tubes are a good value and sound good also.

If you have a diecent budget, SED =C= 6L6's are really nice, but they run $140ish for a set of power tubes. Genelex Gold Lion are also nice.

You may want to get a JAN-Phillips/GE 5751 for the PI (phase inverter) to help tame the gain. They run ~$30ish each. JJ does make a new 5751 that is $15ish and it has gotten pretty good reviews.
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#11
Quote by Robbgnarly
You may want to get a JAN-Phillips/GE 5751 for the PI (phase inverter) to help tame the gain.



I don't want to tame anything about this amp

i think i'll go with JJs, my budget is fairly tight
1997 Ibanez RG550 w/ EMG 81 bridge - C standard
PEAVEY 6505
Mesa Rectifier slant 4x12
#12
Quote by BoneAndDream
I don't want to tame anything about this amp

i think i'll go with JJs, my budget is fairly tight

Trust me, using a 5751 in the PI is a really good thing with the 5150 amps. another option is to use a JJECC803 in V1 to help the cleans out.

If your in the USA, www.eurotubes.com has nothing but JJ tubes and they even have "sets" of tubes for the 5150/6505 amps with several diff preamp and power amp combinations depending on what you want. I order most of my JJ tubes from them.

You can get the Rubytubes 12ax7 from Musiciansfriend (it is a high gain tube but it is miss labled on the site) it is actually a JJ 12ax7(ECC83)
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#13
^ +1 A JAN Phillips 5751 would be nice if the budget wasn't tight and you are correct, Eurotubes sells nothing but JJs.

Quote by Tremolo Bum
What channel are you playing on and does the volume change when this problem happens?

My guess here is a bad preamp tube.


To start troubleshooting I would simply remove and reinsert all the preamp tubes. If you have contact cleaner on hand spray that in the socket.

First of all the symptoms sound like the power tubes are dying to me. Second, do not spray contact cleaner into the sockets. Spray it on the tube pins and then work the tube in and out to clean it.


TS - this may be redundant now but if you are on a tight budget I would get a 'matched quad' of JJ power tubes and get one or two JJ preamp tubes if you have extra money. Keep all old tubes as spares.

www.eurotubes.com
www.dougstubes.com
www.tubedepot.com

If you can't wait - then go to Guitar Center and pay more for whatever they have on hand, as long as they are matched.
Last edited by 311ZOSOVHJH at Mar 21, 2013,
#14
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#15
Quote by 311ZOSOVHJH

First of all the symptoms sound like the power tubes are dying to me. Second, do not spray contact cleaner into the sockets. Spray it on the tube pins and then work the tube in and out to clean it.


It's really anyone's guess without seeing the amp. Mine did a very similar thing, got very fizzy, little to no bass, sounded like shit. Turned out a few preamp tube replacements fixed it. The power tubes were fine. Hopefully that's the case here, although the sign that the problem occurs after the amp has been running and goes away sometimes after could definitely be a power tube issue.

Also, slightly unrelated, why not spray into the tube sockets? That's what I've always done. I guess it could depend on the cleaner used, but mine evaporates very quickly and leaves no residue. The best option would be to use a pipe cleaner or something to clean it but then again, I can be a bit lazy

Jackson RR3 Rhoads and DK2M Dinky
Peavey 6505+ w/ Avatar 212 cab
Ibanez TS9, ISP Decimator, MXR 10 Band EQ
-Digitech RP1000
#16
Quote by BoneAndDream
I don't want to tame anything about this amp

i think i'll go with JJs, my budget is fairly tight


Haha, it takes A LOT to tame a 5150/6505. I highly recommend the JJ 5751 in either V1 or the PI.

Out of all the tube upgrades I've done to mine, the 5751 in V1 probably had the most noticeable effect. By the way, I also run a 12AT7 in the PI position (which has even further reduced gain compared to a 5751) and I still run my preamp gain at around 4. Still, it's blisteringly brutal; more gain just muddies it up. What I've noticed with the 5751 especially is that the distorted tone is just a bit clearer and cleaner, rather than a sometimes wooly mess as with all 12AX7s. I play a lot of big barre and inverted power chords and with the 5751, I can hear the individual notes of the chords a lot better, rather than the whole thing blending together. It's a subtle difference, but I like the sound much better.
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#17
If you are running a head give a JJ ECC803 a try too. They have marginally less gain than a ECC83S but they also have a bit more clarity and sparkle to them - plus of course, they are low noise which is always a good thing in a 6505/5150.
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#18
something else happened just now

all of a sudden i lost volume and it sounded like a blanket was thrown over it.

i bought the one year coverage from gc when i purchased the head, should i take it to them?

or should i just get all new tubes and see what happens?
1997 Ibanez RG550 w/ EMG 81 bridge - C standard
PEAVEY 6505
Mesa Rectifier slant 4x12
#19
Still sounds like a bad tube.

This is why having spares saves you form these decisions.

At least buy 1 preamp tube and switch it around. They are $10.
#20
but what if it's more than one bad tube? what if some of the power tubes are going bad too? wouldn't it be best to just replace them all?
1997 Ibanez RG550 w/ EMG 81 bridge - C standard
PEAVEY 6505
Mesa Rectifier slant 4x12
#21
I'd replace them all, myself but I'd do it systematically so you can identify what actually went bad. Then you can keep the others as spares.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band