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Repaired and upgraded a Fatman iTube hybrid integrated amp.Faults reported/work requested:- New volume pot required; ins...
03/09/2026

Repaired and upgraded a Fatman iTube hybrid integrated amp.

Faults reported/work requested:-
New volume pot required; install upgrade mods.

Removed base covers for access.
Visual inspection for distressed/degrading components and solder joints, etc. Removed ancilliary and main PCBs for rework. Replaced the volume pot with a new 16mm A100k dual gang. Replaced the HT power filter capacitor with a new Rubycon 400BXW100MEFR16X35 100µF, 400 V, 12000 hours @ 105°C.
Replaced the magic eye power filter capacitor with a new Rubycon 350BXW33MEFR10X25 33µF, 350 V, 12000 hours @ 105°C. Replaced 3x low voltage power filter capacitors with new Nichicon UPW1V222MHD 2200µF, 35 V, 8000 hours @ 105°C.
Replaced the 2x interstage coupling capacitors new Vishay MKT1813510255G 1.0µF, 250V metalised polyester. Replaced the 2x input series resistors with Vishay RN60C1002B 250mW, 10k +/-0.1%, +/- 50ppm/°C nickel-chrome (metal film) precision resistors. Replaced the 2x lower leg feedback divider resistors with Vishay AC03000005600JAC00 3W wirewound resistors. Reinstalled the boards for test.
Checked DC voltages and midpoint voltages all OK (both channels). Connected loudspeakers and an audio source; checked all operating OK.
Checked output voltage, symmetry and channel balance OK.
Concluded audio and function tests OK, re-fitted the cover.

Repaired and serviced a Roland Jazz Chorus 120 guitar amp.Fault reported:-Not powering on.Confirmed fault reported, also...
03/09/2026

Repaired and serviced a Roland Jazz Chorus 120 guitar amp.

Fault reported:-
Not powering on.

Confirmed fault reported, also noted reverb tank hanging loose.
Extracted the amp chassis for inspection/repairs.
Visual inspection for distressed/degrading components, solder joints, etc. Noted and replced blown DC fuses wih 2x new T3A15/20mm (found a nut loose inside). Cleaned/deoxidised all of the control pots, jacks and switches. Fixed the reverb tank in place with the appropriate rubber mounts and hardware. Noted the signal wire broken at the input plug, reworked OK.
Powered up with DBT currrent limiting in place, normal load indicated. Switched to full wall power for continued testing.
Checked all DC voltages, quiescent current (bias) and midpoint voltage OK.
Checked operation with audio, both channels OK.
Checked all pots and jacks functioning correctly.
Noted reverb not working, checked continuity of the transducers - input open circuit. Further investigation revealed a broken wire inside the reverb tank at the transducer, repaired satisfactorily. Checked operration OK.
Checked chorus/vibrato, footswitcing, extension speakers, line out and line inputs all OK.
Checked output and voltage symmetry OK.
Concluded audio and function checks and tests OK, reassembled for final test.

Built a pedalboard to amp loom.
02/09/2026

Built a pedalboard to amp loom.

Repaired and serviced a Fender Frontman 212R guitar amp.Fault reported:-Intermittencies; stuck on drive channel.Confirme...
01/09/2026

Repaired and serviced a Fender Frontman 212R guitar amp.

Fault reported:-
Intermittencies; stuck on drive channel.

Confirmed faults reported.
Extracted the amp chassis for inspection/repairs.
Visual inspection for distressed/degrading components, solder joints, etc. Removed the PCB, reworked all the usual areas for dry/cracked solder joints. Cleaned/deoxidised all of the control pots and switches Reinstalled the board for continued testing.
Still stuck on the drive channel - noted pieces of broken jack stuck in both the socket on the amp and that on the foot controller. Successfully removed the broken pieces, operation now good.
Noted a broken RCA socket at the reverb tank input; removed the tank for repair. Fitted a new socket onto the existing mini PCB and wired OK. Checked operation OK, reinstalled the tank back into the bottom of the cab.
Checked all pots and jacks functioning correctly
Checked reverb, footswitching and loop all working correctly.
Checked output and voltage symmetry OK.
Concluded audio and function checks and tests OK, reassembled for final test.

Repaired and serviced a Peavey Classic 30 guitar amp.Faults reported:-Very noisy.Removed amp chassis for inspection/repa...
01/09/2026

Repaired and serviced a Peavey Classic 30 guitar amp.

Faults reported:-
Very noisy.

Removed amp chassis for inspection/repairs.
Confirmed the fault reported, noted output valves starting to red-plate.
Electrically tested all valves OK.
Visual inspection for distressed/degrading components, solder joints, etc. OK.
Checked all voltages without the output valves, fond -14V bias missing. Located and replaced failed resistor R66 (15R/5W). Rechecked voltages, now OK. Installed the valves for continued testing.
Checked all pots and jacks functioning correctly.
Checked reverb, footswitching and loop operation OK.
Checked output voltage and symmetry OK (67V p-p into a 16Ω resistive load = 35W RMS).
Concluded audio and function checks and tests OK.
Reassembled for final test.

Tested and serviced a ProAmp Viper guitar amp.Fault reported/work requested:-Sounds dirty on clean channel.Extracted the...
29/08/2026

Tested and serviced a ProAmp Viper guitar amp.

Fault reported/work requested:-
Sounds dirty on clean channel.

Extracted the amp chassis for inspection.
Electrically tested both valves OK, reading good and matched.
Visual inspection for distressed/degrading components, solder joints, etc. OK. Tightened loose input jack.
Checked all DC voltages present and correct.
Checked bias voltages at the test points all good.
Checked operation with audio.
Cleaned/deoxidised noisy tone pots, checked operation OK
Confirmed all switches, pots and jacks functioning correctly.
Checked reverb, loop and footswitching OK.
Checked output voltage and symmetry OK (84V p-p into a an 8Ω load = 110W RMS, checked on clean channel).
Concluded all audio and function tests OK, reassembled.

Repaired, refurbed and serviced Quad 33 and 303 pre- and power amps.Fault reported/work requested:-For refurb (internals...
28/08/2026

Repaired, refurbed and serviced Quad 33 and 303 pre- and power amps.

Fault reported/work requested:-
For refurb (internals).

303 power amp:-
Removed the cover for access.
Visual inspection for distressed/degrading components, solder joints, etc. Noted the main filter capacitors and output couplers degrading badly (as usual) - replacement necessary. Removed the old capacitors pending replacement. Cleaned loose dust and debris from the interior. Replaced/upgraded the 4x 2,000uF/100V power filter and output coupling capacitors with a 3x new 10,000uF/100V (no need to fit 2x 10,000uF to replace the power filters). Replaced 6x electrolytic capacitors on the driver boards with new.
Checked and set regulated DC voltage for 67V, set midpoint and quiescent current OK (both channels).
Connected an audio source and the workshop monitoring system. Checked all inputs and outputs OK.
Checked output voltage, symmetry and channel balance OK.
Concluded functionality OK, reassembled.

33 pre-amp:-
Checked operation of the pre-amp before commencing. Noted numerous intermittencies random noises and a channel imbalance.
Upgrade and capacitor replacement recommended.
Commenced capacitor replacements and upgrades:-
Removed power supply and increased overall headroom by upgrading the original 11V supply to 16V, also much improved supply filtration with significantly larger capacitors.
Adapted the phono board for the increased PSU voltage and replaced 9x electrolytics; replaced R305/308 with metal film for improved stability.
Adjusted the sensitivity of the phono adaptor to compensate for higher gain of the phono board.
Replaced the 2x small electrolytics (balance coupling) on the motherboard.
Replaced 6x small electrolytics on the output boards; adjusted the sensitivity by replacing 4x resistors.
Performance of the unit significantly improved by updating 4x resistors (with metal film) and 4x capacitors on the tape adaptor board (also in circuit with the other line inputs).
Re-tensioned the edge connector contacts and cleaned/deoxidised the gold plated contacts on the boards and the control pots. Reassembled for test.
Checked operation OK, no further issues.
Checked all inputs and outputs OK.
Concluded audio and function tests OK, refitted cover for final test.

Repaired an Aria Pro II Magna MA40 guitar.Faults reported/work requested:-New 25k volume pot required; wires off inside....
27/08/2026

Repaired an Aria Pro II Magna MA40 guitar.

Faults reported/work requested:-
New 25k volume pot required; wires off inside.

As above, fitted a new 16mm A25k (22k) pot.
Re worked the wiring as necessary.
Checked operation OK.

Repaired, serviced and set up a Goldring Lenco GL78 turntable.Fault reported/work requested:-Channel dropping out; aut s...
26/08/2026

Repaired, serviced and set up a Goldring Lenco GL78 turntable.

Fault reported/work requested:-
Channel dropping out; aut stop not working; service as necessary. Noted output cable very short.

Removed the base and platter for access, releaased all transit screws.
Checked and cleaned the drive idler and motor spindle OK.
Checked the motor for excessive noise and wear OK.
Cleaned all old oil from the centre bearing; topped up with new Velocite No 6 light machine oil. Noted the rubber auto stop "noodle" missing from the mechanism (probaly perished and dropped off as usual) - fitted a suitable piece of rubber sleeving. Replaced the short lead with new, also renewed the ground wire. Reinstalled the platter; checked operation OK. Set the transcriptor level OK and fitted the base.
Confrmed channel drop-out due to a fractured right channel signal connector at the cartridge - replaced with similar type.
Checked rotational speeds OK.
Found the [very old] Goldring G820 carteridge not performing very well - replaced with a new Audio Technica AT-3600L and set-up OK. (The Goldring and the two spare Audio Technica cartirdges are now all obsolete.)
Checked operation OK with 33rpm records.

Repaired and serviced a Harman Kardon 630 receiver.Faults reported/work requested:- Went bang and released smoke!Removed...
24/08/2026

Repaired and serviced a Harman Kardon 630 receiver.

Faults reported/work requested:-
Went bang and released smoke!

Removed top and base covers for access.
Visual inspection for distressed/degrading components and solder joints, etc. Noted an exploded electrolytic and 2x burned resistor on the 21V regulator board and also two burned resistors on the associated 14V/12V dropper board. Removed the boards for rework. Noted the cause of the issue - some work has already been done on the reguator board, one transistor had beeen fitted the wrong way around, eventually causing catastrophic failure. Replaced 2x transistors, 4x resistors, 4x capacitors, 2x diodes ad 1x zener.
Powered up with DBT current limiting in place - normal load indicated. Checked DC voltages, midpoint and quiescent all OK (both channels). Switched to full wall power for continued testing. Rechecked the voltages.
Connected loudspeakers and an audio source; checked all operating OK.
Checked output voltage, symmetry and channel balance OK.
Cleaned/deoxidised pots and switches satisfactorily.
Noted function indicator lamps lighting when they shouldn't - broken rotary switch element, repaired OK.
Noted the radio channels not aligning with the pointer indication - adjusted the pointer to the correct position on the dial cord.
Concluded audio and function tests OK, re-fitted the covers.

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22 Fore Street, Barripper
Camborne
TR140QR

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Thursday 9:30am - 7pm
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