no output from power amp?

My Peavey Classic 50/50 tube power amp finally came in Saturday. I put in some new JJ tubes as soon as I got it and had band practice that night, and it worked flawlessly. Until I tried to set it up different. I did have it running stereo, but then tried to run it mono, and no sound would come out o fit. Everything turns on fine (I haven't opened it back up yet, but even then I wouldn't know what to look for), I just don't get any sound. I ended up having to use my classic 50 combo amp for my power amp for last nights practice. Any idea's why it's not sending a signal/power to my speakers?

I think I might have fixed it, but I wont know for sure until Saturday :( . When I got home from work yesterday, I opened it up and found that one of the fuses was blown. I'm guessing this amp is close to 10 years old, and still has the original... everything(minus the new tubes I immediately installed when I got the amp). So, I'm guessing I should go on and put in all new fuses.

One more question... How can you tell if caps are going bad? What sound characteristics will this have on an amp?

Originally Posted by: PRSplayaI think I might have fixed it, but I wont know for sure until Saturday :( . When I got home from work yesterday, I opened it up and found that one of the fuses was blown. I'm guessing this amp is close to 10 years old, and still has the original... everything(minus the new tubes I immediately installed when I got the amp). So, I'm guessing I should go on and put in all new fuses.[/QUOTE][font=trebuchet ma]I'd want to know why that fuse blew when you set up for mono operation. Check your setup.[/font]

[QUOTE=PRSplaya]One more question... How can you tell if caps are going bad? What sound characteristics will this have on an amp?

[font=trebuchet ms]As caps age, they don't charge and discharge as quickly, so they don't fliter out the AC line ripple as well. The DC supply will 'sag' a bit more (which can sound kinda nice), and AC hum will get increasingly louder as they deteriorate.

How's the Rock Master?[/font]

The Rock Master is wonderfull. I put in some new JJ tubes and it livened it up a bit. The clean channel is nice and fat and really compliments my PRS very well. The crunch channel is perfect for those slightly dirty, but still hear every not loud and clear. The ultra channel will peal the paint off the walls! I might have the gain at 10 o'clock and it is perfect. I have the eq set up for an in your face, mid punchy, knock you on your butt, heavey sound, and then when I want a heavier more metal sound I use the g-major's eq to scoop the mids just a tad and boost the low end a tad, almost like haveing a forth channel. While it was working, the power amp and the rockmaster complimented each other very well. Hopefully I'll hear some more of those sweet tones this weekend, instead of having to use my classic 50 combo as a power amp to run my cab.

It also records fairly well too. At home I run the RM and GM to a Berhinger direct box that emulates a 4x12 cab and then into my computer. It sounds good that way, but not as good as an actual mic'd cab, but it get's the job done.

Did you re-bias after putting in the JJs, how do you like em ?

Im planing on getting a set for my TSL next month and would love to know how they worked out !

They're fixed bias EL84's, so no need to re-bias the amp. Your TSL on the otherhand uses EL34's which will need re-biasing.

JJ tubes are great. I tell Bob at eurotubes how things sound, and then how I want them to sound, and he delivers! My classic 50 2x12 combo has an awsome chunky metal rythm sound now. Before it was more like Skynyrd or 38 Special type overdrive (which it can still do very very well), but now the clean channel breaks up a bit earlier than before which gives it a really fat/thick tone, and the dirty channel can go from dirty blues to metal chugga chug(especially through my marshall 1960A 4x12 cab).

New tubes can really liven up an amp, and if you want can drastically change your sound.

Originally Posted by: PRSplayaThey're fixed bias EL84's, so no need to re-bias the amp...

[font=trebuchet ms]Fixed bias? That usually means that the bias is set (fixed) to a particular value by adjusting a special grid power supply. This is the kind of bias circuit that must be adjusted to suit the tubes. Self-bias is a circuit design that doesn't need to be adjusted. Please be very sure about which kind of bias circuit your amp uses![/font]

Bob at eurotubes told me all I have to do is plug and play.

Originally Posted by: PRSplayaBob at eurotubes told me all I have to do is plug and play.

[font=trebuchet ms]All rightey, then. Enjoy![/font] :D

the new fuses did the trick :D

here we go again :mad: ! It did fine Saturday, but yesterday when I turned it on, none of the led's would come on. It played fine for a few min. then I turned it on standby for a while, and when I came back to play.....NOTHING! So, I opened it up, and no fuses were blown, and all the tubes looked fine. Could the output transformer have blown? :( This thing has been nothing but trouble since the day I won it on ebay. Anybody have any idea's?

[font=trebuchet ms]Whatever is causing the trouble is intermittent. That makes it hard to nail down because you can't find it unless it misbehaves while you're looking at it. I'm guessing there's a loose connection somewhere in the power supply wiring. This is dangerous stuff to mess around with. Unless you have some training in this kind of thing, I suggest it's time to take it to a qualified tech for a look-see.[/font]

Thanks for your help. To the tech it will be going! I guess the RM is just too much for it...lol Good thing I still have my combo I can use to drive my cab with :o

Originally Posted by: PRSplaya... I guess the RM is just too much for it...lol ... :o

[font=trebuchet ms]That's what happens when you pull those Gain knobs out to get the extra boost![/font] :D

he he, me likey though :D

I have it pulled out on the Ultra channel and pushed in on the crunch channel. I'm still stoked about the tone's I'm getting with my setup (when it works).

I just got word from the repair shop that the OT is gone, and they can't find another one to replace it :confused: !! I find that hard to believe :mad: What should I do? Should I keep worrying with it, or sell it for whatever I can get for it, or just throw it in the closet? I'm sick of all this crap! I'm going to look for a new head next week.....heck, maybe even another XXX. I still kick myself in the rump for selling the one I had :rolleyes:

wow bummer !

Id stick it in a cupboard and have a cogitate for the next couple of weeks

cogitate :confused: what's that?

oh a sit and a think !

hey, Doc, how good is 8thStreetmusic? They've got a Peavey XXX head for $100 cheaper than anybody else.