Need help trouble shooting peavey xl-500 mix amp

[Enzo]

"G" means green, some companies use "PBF"

ALl that means is the parts are lead free and meet the newer lead standards. The parts are completely interchangable with the non-G types. SOmetimes the older non-G ones are cheaper, so I buy them.

VRs are your 15v regulators. Are they bad? DO you not have your 15v rails?

Says on the schematic LM340 and LM320, and by context, the 15v versions of those. LM340-15 is the same thing as a 7815, and LM320-15 is the same thing as 7915. All are 15v regulators in a To220 package.

[captainlee]

Hi Enzo,

Well it was a productive day I removed:

4 of the power transistors Q6 Q7 Q10 Q11 on the heat sink

The Q5 5331 and Q6 5332 ( I need these part #s)

14 pin TL04CN all pads intact.

Checked all the .33 ohm 10 watt resistor all read .33

R20 R22 R23 all match ohms test.

What do you want me to do next besides order the parts??

I made a mistake asking about the VR1 and VR2 they are fine. Sorry.

[Enzo]

Wasn't the TL074 in a socket already?

5331 and 5332 are Peavey house numbers. peavey will sell them to you.

I mentioned 5331 is an MJE243 in post #12. 5332 is an MJE253.

[captainlee]

No I diidn't remove the socket, just the part.
Ok so I'll get the parts talk to you in a week or so. Thanks again Cap.

[captainlee]

Hi Enzo,

I've been checking the board more and all the big diodes are ok but a few of the smaller ones are showing current flowing both ways ?
what is the part number for these smaller diodes? they all seem to be the same.
For instance CR 6 tests closed both ways. can you check these on the board?

Thanks in advance Cap.

[Enzo]

I bet CR7 tested both ways also. Note the schematic, CR6,CR7 are two diodes connected back to back. So naturally, when you test one backwards, you are testing its mate forwards at the same time. Your test sounds like they are good.

Read the schematic, lower left. Note it reads

"Unless otherwise noted:
All diodes are 1N4148"

And if you test a part in-circuit, and are not convinced, then unsolder one end and lift it. Now you can retest without the circuit involved.

[captainlee]

Hi Enzo,

Thanks for your info I did find that part number finally earlier today on the schematic and ordered them at .05 cents each from peavey$1. also ordered the rest of the parts from mouser today.$28. So I'm waiting for parts now.
hope yopu are around when I install the new parts )( Cap.

[captainlee]

here is the pre amp schematic if anybody's interested. Cap.
http://i657.photobucket.com/albums/u...SCHEMATIC1.jpg

http://i657.photobucket.com/albums/u...SCHEMATIC2.jpg

http://i657.photobucket.com/albums/u...SCHEMATIC3.jpg

http://i657.photobucket.com/albums/u...SCHEMATIC4.jpg

[newbywankenobi]

Filter caps

These are two new 6800 uF caps, 63 vdc, replacing the original 5000 uF caps. $3.75/ea @ Mouser. Also added 1 uF caps in parallel as per Peavey restoration/mod site recommendation, $1/ea @ Mouser. Works good, quiet. Loud when cranked. Pots a little scratchy and reverb tank has open circuit in the output coil windings, but I can live with that for now. Feeding it guitar through a Zoom G2 effects pedal (with reverb..), Fender 4 x 12" speaker cab.

If you have not replaced these caps I would recommend it, Peavey tech said they are most common cause of the deafening buzz in speakers in this model, go bad after several years. It was definitely the prob with mine, no more dc or ac at the mains outputs.

Know of a cheap place to buy reverb tanks?

Ethan Newby's Photos - Guitar stuff | Facebook

[captainlee]

newbywankenobi
O Hi again Well thank you so much for all your information very useful for me. I will most certenly install the new large caps but I don't understand where the smaller caps ones go? ? exactly? coulld you draw me a diagram? please. thanks in advance for that.
I took electronics in high school learned all the part names and ohms law ect but really never used it untill i bought that mixeramp on ebay. the guy
said in the ad that it worked good xccc nvbnm,cvnnm i don't think so.....I called him on the phone and asked him if he tried it out before he listed it he said he did, I said how did you do that when there wasn't a fuse in the holder he said he didn't know but it worked. ha ha ha ha ah yak yak. any way I'll break even when i'm done buying parts probably $100.00 total.
I don't know where to get those reverb boxes but i'll keep an eye looking for you. I may need one my self i haven't checked mine yet but its there.
As for how are things going I am starting to feel a lot better about working on the circuit board now after removing those power transistors so the rest should be a breeze as long as I get the right parts and get the joints soldered right.
I am just waiting for the transistors, resistors ect.from mouser now. Also thanks for the encouragement it really helps. Cap. I added the pre amp schematic i bought on the web maby you will use it.

Ilooked for the caps on mouser could you give me the part numbers ?? TIA CAp.

[captainlee]

In case any body is interested newbywankenobi gave me this info for the upgrade on the caps. ect. Session 400 geek page

same basic type amp mixer from peavey according to newbywankenobi. I like the information this page gives. now if i could find it for my marshall 100 hdfx? I thank him for his input. should have the rest of the parts end of week for those lurking around. HA Ha Ha. you know who you are.

[captainlee]

Wrong size caps ?????

Enzo do you know the answer to this question.

I ordered some electrolytic caps from mouser but they are 1/2 SMALLER the physical size of the original caps will they work or do I need to change to a larger size? HERE ARE THE SPECS AND ARE NOT LEAD.

PC board 2 or 4-pin snap-in; optional 4 or 5-pin straight terminals.
Capacitance range: 56 to 270,000μF.
Voltage range: 6.3 to 450VDC.
Category temperature range: 40C to85C for 6.3 to 100V; 25C to85C for
160 to 450V.
Leakage current: 0.02CV(μA) or 3mA, whichever is smaller, after 5 minutes at20C.
Standard capacitance tolerance: 20%
Nominal case size (DL): 2220mm to 4080mm.
Rated lifetime: 2,000 hours at85C with the rated ripple current applied.

NEW ones ARE: 661 ESMH630VN682MR MFG PN ESMH630VNN682MR40T
6800 UF 63 VOLTS UCC ALUMINUM ELECTROLYTIC CAP SNAP IN .

OLD ONES ARE PART NUMBER 70320039 5000 MFD 55 WVDC460 8028 85*C

IF I DO NEED TO RE-ORDER ANY IDEA OF THE PART NUMBERS FROM MOUSER?
Cap.

[captainlee]

Every one Disregard this last post I have solved the problems. Thanks now just waiting for parts again.

[Enzo]

Size doesn;t matter, only ratings. I think we mentioned that the new caps will be smaller.

The old caps are 5000uf at 55v.

Those are no longer made.

6800uf at 63v is a perfectly fine replacement.

And yes, they will be a lot smaller than those old orange juice sized cans that came with the amp. technology has advanced in the last 30 years.

[captainlee]

Waiting for parts again

And Hello to you Enzo, hope you had a great new years eve!!!!!

Well I;m getting better at searching for parts.


Are the gaskets that are under the power transistors to be reused under the new transistors, before I solder them in?

The new caps i ordered are coming from :

C25 & C27 6800uF/63v Digi-Key - 493-1363-ND (Manufacturer - UVZ1J682MRD)

these caps are the exact ones. that the other gentlemen has and his works so i'll just use these. the parts will be in mon or tue via priority usps. Cap.