The Peavey T-max appears to be hybrid with a Solid State power amplifier. If it's a loud humm not affected by the volume control, disconnect the speaker immediately or it will be destroyed, and check for DC on the output terminals. If DC is present more than a few millivolts, then it is likely one or more output devices haxe expired. You will need a schematic diagram and a conversion table for the proprietary codes Peavy use for their semiconductors. Tony
As I dont know where in Australia Rod lives, I can only use the information displayed on his web site and that is what he quotes. UK VAT must also be added (20%) and also the local Royal Mail charge for collecting this from me. This is not known but Rod estimates it at about £8.00. The P68 board costs US$32 (£22 approx). Unfortunately I am not prepared to pay this for one board no matter how good, even though the ones I have used before are certainly good quality.
Yes I know about Rod and have already used a number of his boards, but I am not prepared to pay his ridiculous shipping charges of US$24.50 from Oz to UK for a board when all he has to do is stick it in an envelope.
Something odd about this amp. The blurb here https://www.thomann.de/gb/harley_benton_gpa_100.htm says '130 watts into 8 ohms or 210 watts into 4 ohms,' however the rear of the amp shows the power consumption - 230 v ~50Hz 0.6A which equals 138w . So how can you get 210 watts from a 138w supply >>100% efficiency. Even 130w from 138w is 94% just about achievable for Class D amplification.
Looking at the drive current through Q4 only 8mA approx, I would suggest that the output transistors are Darlington transistors, in which case 3055/2955s wouldn't be suitable. If they are TO3 cases try MJ11015 pnp and MJ11016 npn as replacements if you can get them. If they are plastic types then TIP142 and TIP147 would work.
You appear to have some parts missing from your amplifier board. Including the input level pot. The g1xon is probably putting out too much volume for your amplifier so you will need someway of turning it down. What gain did you set for the LM386?