faisal":259zfndl said:
Please list your DIY mods, upgrades, maintenance techniques for the 5150.
Basicly...
Bias mod - Peaveys are biased very cold (Bias is basicly the amount of electricity pumped into the valves) cold amps can sound a bit sterile, jacking up the bias opens up the amp, makes it feel more warm and natural.
That's the only real DIY mod I would reccomend.
I plan to re-tube my head and also try the different tube in the PI mod and the Bias Mod.
The 5150s and 5150 IIs especially are very bright, mid heavy amps. JJs are very dark tubes, so alot of people like the combination, but I don't rate them that highly, I've also heard (and had myself) of reliability issues with them, more so than other brands.
Winged Cs are great. TAD are too. Electro Harmonix are reliable, but don't sound all that fantastic.
Look into 5751 preamp tubes as an alternative to other 12A_7 variations for, I think it's PI. There's a specific combination of different brands that lots of people seem to like, I don't know it off by heart but I could find it for you easily?
Any others ? favorite speakers, cabs, pedals for the 5150 ? Also where is a good place to buy replacement potentiometers and knobs for the 5150 ?
Favourite speakers. Celestion V30s (Or other copies/similarly voiced speakers) They're alot less muddy and fizzy than 'T75s. Eddie Van Halen used Greenbacks, and the 5150 cabs have speakers modelled after Greenbacks, but are notorious on forums like this. I have no experience with Greenbacks personally.
V30s are the way to go in my opinion for 5150s.
Cabs - Mesa 412. Marshall's are decent for the money but you could do better, Orange, Mills etc etc.

Mesa is a good choice and not too pricey.
Pedals - You NEED a noise gate. It's a noisy amp. The Boss NS-2 is the go-to for most people but the ISP Decimater and MXR Smart gate are both better pedals in most people's opinions.
Boost pedals, line drivers, pickup boosters, low gain overdrive pedals, whatever you wanna call them work great.
Tubescreamer style pedals. Ibanez Tubescreamer is a favourite, but most people who have played both say the Maxon OD808 is better, it may even have the same circuit, just better quality componants, the boss SD-1 is a slightly differently flavoured boost and it's what I use, can be modded to the specs of an Ibanez Tubescreamer for about £2 and 10 minutes of your time easily, very DIY friendly.
Run the pedals with the volume on MAX and the gain on ZERO and tone in the middle to start off with, then you can adjust to taste later, the point of a low gain overdrive infront of the preamp is to push the tubes and colour the EQ, tighten up the bass and change the overall tonality slightly, every boost does this slightly differently.
Never heard of someone needing to replace the pots on a 5150, you can get chicken head knobs anywhere. Don't worry about that.
I hope this has helped. Any questions don't be afraid to ask me with my limited experience but particular interest in 5150s.
Cheers,
Torquil.