Peavey T-MAX head

[EdBo]

Heyyooo, first time TalkBass poster here, I'm working on my buddy's TMax500 with some seriously weird issues goin' on, that I believe is tangentially related to the cooling fan.

First question, can anyone tell me if the fan is supposed to work as an intake or outflow? Because this particular one has it wired for intake at the moment, which seems weird to me as it's resulted in an A$$load of dust all over the circuit, pots, and wiring.

Second question, has anyone experienced problems with intermittent short-circuiting when in normal operation, or when firmly tapping the chassis? I believe that the aforementioned dust has caused some intermittent shorts to develop around the input and gain sections, which makes the Amp crackle loudly while triggering the red "Clip" light. The crackling sound is particularly bad when playing anywhere above master volume 3, and basically makes it unplayable.

Awesome Amp, would definitely appreciate any input on these questions if any one has experienced this issue or has some wisdom on the subject! Thanks~

Barbeau Audio

My fan intakes. I've never had any problems out of mine. I opened it up when I got it from the local Pawn shop 4 or 5 years ago to clean it, that's all. I hate those intermittent problems. I've found prayer and meditation seems to help, good luck.
Eddie

 

[Bass Butcher]

I was just looking up T-Max stuff because I am considering selling one or both of mine. I have two heads, two of the 2x10 cabs and one BW bottom cab. Took the best components and have one at 100%, with the footswitch and a quiet fan . I'd really like to get my paws on the stand alone pre amp. Having two of the top cabs I could mount a 500 - 700w mono power amp in one to drive the bottom cab through the on board crossover, which would be pretty sweet but take the total weight up to around 300 pounds, lol
I replaced the Sheffields with a pair of Eminence Betas that I had in another combo and highly recommend them as replacements. Good bang for your buck and having 200 watt speakers with about 10% better efficiency is a definite improvement. Two out of my four Sheffields had a coil lead snapped off at the tab solder joint, due to age/vibration, so something to watch for there if a speaker 'fails'. I'm going to use a pair of them in the 2x10 combo cab I took the Beta's from. The Sheffields are nice sounding speakers but under powered for the T-Max.
Most amps with fans have the fan draw air into the cabinet which also sucks in the dust. I remount them so they draw the hot air out instead. I started doing it with cpu/heat sink fans on computers a couple of decades ago, for the same reason and do it with all case fans on amps and computers now. Definitely a potential issue with the T-Max, as most of that dust winds up on the input power pcb and components on it. The fan volume 'issue' with the T-Max is a common complaint but that is due to the fan being old and having a lot of miles on it. They are bearing fans and that is to be expected. If it isn't too bad you can lube the bearing race from outside the case with something like WD 40 or aerosol lithium (lithium is better). A proper replacement fan isn't cheap, as the spec is for around 32 - 34 cfm, iirc.
The manual and schematic for the T-Max are available online too.
https://assets.peavey.com/literature/manuals/80302264.pdf

 

[Bass Butcher]

Had to look at my heads re the 500 vs 550 watt thing. Turns out I have one of each. 500w is older and 550w is newer is what it boils down to. They probably made some slight component changes during the years it was produced. I'll check the power transformer numbers, etc., as I want to switch out the 12ax7 in the 550w. It is still wearing the original MIC one.
Slight correction to my last post, the Eminence Beta 10-A's are 250w rms, 500w prog, compared to 75w rms, 150w prog for the Model 121 Sheffields. All four of my Sheffields are the newer ones (96000296). The Beta's make getting a slave power amp to drive the bottom cab and using the crossover much more viable. I was half way through posting the complete rig with the 550w head on Kijiji but I've changed my mind. I'll sell the other head and 2x10 instead, once I'm done servicing it. Even though I'll mostly be using my Traynor YBA-4 I just cannot justify selling the Peavey rig. It would cost me two to three times as much as I'd get for it to replace it, if I bought used. Cheaper to just go buy a good dolly for moving it

 

[Bass Butcher]

Here is the verdict on the 500w vs 550w heads. On a quick inspection the only difference appears to be a code on the power amp transformers. Both are labelled 705-28754 but the 500w is 695-9715 C18 and the 550w is 695-9526 C18. A few more windings on the latter? 500w on the left, 550w on the right...

 

[South Mad Sab]

I had a T-Max 210 combo with a Peavey 115.... great amp, used it on tour from '03 to '07. HOWEVER, It definitely took 2 guys to load it in and out of venues. Also, I blew out all the speakers 2 or 3 times at different points. Another issue, I blew the internal fuse a few times.

 

[Bass Butcher]

I had a T-Max 210 combo with a Peavey 115.... great amp, used it on tour from '03 to '07. HOWEVER, It definitely took 2 guys to load it in and out of venues. Also, I blew out all the speakers 2 or 3 times at different points. Another issue, I blew the internal fuse a few times.

I almost listed it on Kijiji this weekend but changed my mind. I am going to buy a good dolly for it though, lol No point in putting wheels on the bottom cab, as the top cab weighs 30 pounds more. I have my eye on a Peavey PV 500 power amp to drive the bottom cab now, which will put the amp load at 4 ohms instead of 2 and allow me to use the crossover. The 500 is a perfect watts/ohm match but won't fit in the 2x10 shelf and I might go with a different power amp to do that. Then I would stack all three cabs and have a 4x10 and one 15" rig.

 

[South Mad Sab]

I almost listed it on Kijiji this weekend but changed my mind. I am going to buy a good dolly for it though, lol No point in putting wheels on the bottom cab, as the top cab weighs 30 pounds more. I have my eye on a Peavey PV 500 power amp to drive the bottom cab now, which will put the amp load at 4 ohms instead of 2 and allow me to use the crossover. The 500 is a perfect watts/ohm match but won't fit in the 2x10 shelf and I might go with a different power amp to do that. Then I would stack all three cabs and have a 4x10 and one 15" rig.

I still have mine, it gets used maybe once every couple years (reunion shows, LoL). The bottom 15" is still blown and has collected dust for over 10 years. I have a completely different rig now, just as heavy, but different.

 

[cheechi]

I have my eye on a Peavey PV 500 power amp to drive the bottom cab now... The 500 is a perfect watts/ohm match

is the PV500 the same power section that's in the T-Max? I mean it probably doesn't matter, it's more just out of curiosity I ask.

I'd really like to get my paws on the stand alone pre amp.

I want to point out, the T-Max allows you to use either one or the other or both of the pres via a switch and the Max preamp uses a blend knob. It's not a night and day difference but if you are used to it one way vs the other it can be limiting. Worth pointing out with the T-Max with the tube pre only is a pretty good Bassman clone all things considered. The Max pre even with the blend all the way to tube doesn't get quite there the same way the T-Max does with the switch on tube only. It's still basically the Bassman sound.

 

[Bass Butcher]

is the PV500 the same power section that's in the T-Max? I mean it probably doesn't matter, it's more just out of curiosity I ask.


I want to point out, the T-Max allows you to use either one or the other or both of the pres via a switch and the Max preamp uses a blend knob. It's not a night and day difference but if you are used to it one way vs the other it can be limiting. Worth pointing out with the T-Max with the tube pre only is a pretty good Bassman clone all things considered. The Max pre even with the blend all the way to tube doesn't get quite there the same way the T-Max does with the switch on tube only. It's still basically the Bassman sound.

The PV 500 is a two channel, bridgeable power amp, not a bass head. I'm not too concerned with what other brand the T-Max head or pre amp might sound like. I just want a good tone and tone shaping options. The T-Max tube side gives it and it also gives the option of a rock solid ss pre. I'd be using a V4 or YBA-3 as my benchmarks, not a Bassman. Let's put it this way, I sold my YBA-3 and kept the T-Max. I want the pre amp version or the BBE bmax-t clone simply because they are high quality tube pre amps without a power section.

 

[Bass Butcher]

I still have mine, it gets used maybe once every couple years (reunion shows, LoL). The bottom 15" is still blown and has collected dust for over 10 years. I have a completely different rig now, just as heavy, but different.

Hmm, How much you want for the bottom cab? lol My other option is to make a second complete rig and sell it. Another question for you and you'd be the one to ask. What would you put the room size limit at for this thing for running stand alone - not through mains? Keep in mind the 10's I have in it are three times the wattage of the stock speakers. I was thinking a 150 - 200 person capacity loud venue.

 

[cheechi]

I'm not too concerned with what other brand the T-Max head or pre amp might sound like. I just want a good tone and tone shaping options.

I totally get it and agree 100%. Just thought I could give the most useful comparison I had available since you are considering the preamp.

What I was actually wondering, if the T-Max used the same power section as what's in a PV500, whether your goal was to make an even more powerful T-Max with the Max pre and it. I want to hear my Max through a Classic 60 or 120.

 

[South Mad Sab]

Hmm, How much you want for the bottom cab? lol My other option is to make a second complete rig and sell it. Another question for you and you'd be the one to ask. What would you put the room size limit at for this thing for running stand alone - not through mains? Keep in mind the 10's I have in it are three times the wattage of the stock speakers. I was thinking a 150 - 200 person capacity loud venue.

not for sale... I'll fix it one day...

Depends... Bodies absorb sound, also depends on the band you are in and what you are trying to cut through. There is a reason why I use 2 410 cabs nowadays.

 

[Bass Butcher]

not for sale... I'll fix it one day...

Depends... Bodies absorb sound, also depends on the band you are in and what you are trying to cut through. There is a reason why I use 2 410 cabs nowadays.

not for sale... I'll fix it one day...

Depends... Bodies absorb sound, also depends on the band you are in and what you are trying to cut through. There is a reason why I use 2 410 cabs nowadays.

I used to have a 1850 sq ft rehearsal room/venue that I would pack every once in a while, about 200 people. I'd have bands that rented there do private shows, etc. The Killjoys got noticed by a Warner A+R rep as a result of opening for another band there, to give an example of the type of music. I figure this rig would cut it for that without eating speakers but I probably wouldn't go much further. I kind of like the idea of stacking both top cabs with this rig but I wouldn't want to gig with it if I was the one who had to load it in and out on a regular basis, lol

 

[Raw N Low]

The PV 500 is a two channel, bridgeable power amp, not a bass head. I'm not too concerned with what other brand the T-Max head or pre amp might sound like. I just want a good tone and tone shaping options. The T-Max tube side gives it and it also gives the option of a rock solid ss pre. I'd be using a V4 or YBA-3 as my benchmarks, not a Bassman. Let's put it this way, I sold my YBA-3 and kept the T-Max. I want the pre amp version or the BBE bmax-t clone simply because they are high quality tube pre amps without a power section.

Don't sleep on the other Peavey bass preamps. They are crazy good and can be had for a bargain. The Alpha and T.B. Raxx are both excellent tube bass preamps. I put the compressor the of the bassist right up there with the Roland SIP-301.

 

[cheechi]

In your experience would it be fair to say the Alpha evolved from the Raxx, and that an appropriate way to view the Max is an Alpha with an SS blend? I know they can't be exactly the same as the Max only has one 12AX7 but one imagines there's a reason they didn't continue to sell the Alpha.

Peavey's SS preamps seem to follow a bit more logical evolution from the 70's forward, not quite the exact same preamp circuit but 'Peavey SS preamp' is about as ubiquitous as 'Fender tone stack' across several models. How does the Bassist fit into that potential 'Alpha with a SS blend' idea I suggested? Or would you say it's more likely a 'Bassist with a tube section blend' that became the Max?

 

[Bass Butcher]

Don't sleep on the other Peavey bass preamps. They are crazy good and can be had for a bargain. The Alpha and T.B. Raxx are both excellent tube bass preamps. I put the compressor the of the bassist right up there with the Roland SIP-301.

View attachment 3569079

Wow! That is some rack. There is a 120/120 available on Kijiji near me, was making me drool, lol

 

[cheechi]

can that 120/120 safely be bridged?

 

[EdBo]

can that 120/120 safely be bridged?

Yes. Mono, 240 WRMS. Here's the Manual.

https://assets.peavey.com/literature/manuals/80390045.pdf

 

[cheechi]

assuming bass sounds good through 6L6 power, i have wanted one of those for some time. now i want it more.

 

[Raw N Low]

assuming bass sounds good through 6L6 power, i have wanted one of those for some time. now i want it more.

It sounds fantastic. The manual illustration assumes it will be used for guitar and bass applications.