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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Peavey Bandit, Solo Series, 1981
Normal channel missing just mV of output, same with footswitch supposed
operation, lead ch is fine. Seems to be a rare beast, any pointers to a schematic ? Uses 4x rc4558 opamps ,2x SJ3692 in PA, seems to use an opamp and FET for gating on and off "normal" gain channel. Swapped out the 4558s, as socketed, no change. Thought found prob on underside , one pot pin had never been soldered, just touching contact and some ring crack failures or dodgey looking at pots, but that was just the general crackly performance, clean ch still absent. o/p of one opamp is high, same with swapped version, goes to gate of the FET, which will be the next thing to investigate, if no schematic found. When last powered I did not think to see if the footswitch action gated the opamp o/p. Any other ideas? |
#2
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Peavey Bandit, Solo Series, 1981
On 2017-03-17, N_Cook wrote:
Seems to be a rare beast, any pointers to a schematic ? Is this the one? https://peavey.com/forum/download/file.php?id=14455 -- Adam |
#3
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Peavey Bandit, Solo Series, 1981
N_Cook wrote:
Normal channel missing just mV of output, same with footswitch supposed operation, lead ch is fine. Seems to be a rare beast, any pointers to a schematic ? Uses 4x rc4558 opamps ,2x SJ3692 in PA, seems to use an opamp and FET for gating on and off "normal" gain channel. Swapped out the 4558s, as socketed, no change. Thought found prob on underside , one pot pin had never been soldered, just touching contact and some ring crack failures or dodgey looking at pots, but that was just the general crackly performance, clean ch still absent. o/p of one opamp is high, same with swapped version, goes to gate of the FET, which will be the next thing to investigate, if no schematic found. When last powered I did not think to see if the footswitch action gated the opamp o/p. Any other ideas? Send an email to Peavy at or and ask if they can send you a schematic for your amp. They're usually quick to respond. Give all the nameplate numbers on the amp to get the correct schematic. They are (in)famous for making engineering changes to them and not changing the model or Rev level. Dave M |
#4
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Peavey Bandit, Solo Series, 1981
On 17/03/2017 16:30, N_Cook wrote:
Normal channel missing just mV of output, same with footswitch supposed operation, lead ch is fine. Seems to be a rare beast, any pointers to a schematic ? Uses 4x rc4558 opamps ,2x SJ3692 in PA, seems to use an opamp and FET for gating on and off "normal" gain channel. Swapped out the 4558s, as socketed, no change. Thought found prob on underside , one pot pin had never been soldered, just touching contact and some ring crack failures or dodgey looking at pots, but that was just the general crackly performance, clean ch still absent. o/p of one opamp is high, same with swapped version, goes to gate of the FET, which will be the next thing to investigate, if no schematic found. When last powered I did not think to see if the footswitch action gated the opamp o/p. Any other ideas? How often have I seen this. Everything seems to work component-wise perfectly ok but something is not right. Its due to something I'm doing wrong, either a case of RTFM (no ref to this in the owner manual) or looking too logically at musician stuff. The front panel has a specific section labelled Lead Gain with a line extending out to the PRE pot and POST pot. The next section is marked Normal Gain pot. I was turning both "LEAD" pots to min for f/s engaging of normal and vice-versa for lead channel, but there must be some advancement of the POST pot for either channel to work, only seeing that in the schematic |
#5
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Peavey Bandit, Solo Series, 1981
On 18/03/2017 05:57, Adam wrote:
On 2017-03-17, N_Cook wrote: Seems to be a rare beast, any pointers to a schematic ? Is this the one? https://peavey.com/forum/download/file.php?id=14455 -- Adam Yes, thanks for that. The only number with the model type , on the nameplate, is 82A, and the amp being rated 50W, no reference to 65 anywhere in the amp, c'est la guerre |
#6
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Peavey Bandit, Solo Series, 1981
slightly OT ...
is there a common response in qualifying specs to the naming of BANDIT BLASTER KILLER AMP DOA SONIC GUN et al ..... is this quality ? quality what ? R&R Hard Rock Virgil Fox ? I'd guess that is the intended market but does that work or is the naming just a ploy for cheap outputs |
#7
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Peavey Bandit, Solo Series, 1981
On Friday, March 24, 2017 at 9:03:51 AM UTC-4, wrote:
slightly OT ... is there a common response in qualifying specs to the naming of BANDIT BLASTER KILLER AMP DOA SONIC GUN et al ..... is this quality ? quality what ? R&R Hard Rock Virgil Fox ? I'd guess that is the intended market but does that work or is the naming just a ploy for cheap outputs goo.gl/z03QKX |
#8
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Peavey Bandit, Solo Series, 1981
On Friday, March 24, 2017 at 9:09:26 AM UTC-4, wrote:
On Friday, March 24, 2017 at 9:03:51 AM UTC-4, wrote: slightly OT ... is there a common response in qualifying specs to the naming of BANDIT BLASTER KILLER AMP DOA SONIC GUN et al ..... is this quality ? quality what ? R&R Hard Rock Virgil Fox ? I'd guess that is the intended market but does that work or is the naming just a ploy for cheap outputs goo.gl/z03QKX LOCAL NOISE sez naming here is aimed at a specific age and cultural group ... we can live with this...but what does the oscilloscope say ? |
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