Voltaic Vintage Repair & Restore

Voltaic Vintage Repair & Restore Vintage Audio and Electronic device repair services Electronic repair service and restoration specializing in Vintage Audio Gear from the 60s, 70s, and 80s.

Under $100.00 is repaired automatically. If it's over $100.00 or whatever amount higher than what you set, I would contact you for approval. If at that point you decide not to repair, then it's $40.00 to diagnose.

Yamaha CR-2020 ready for cleaning and restoration!
04/16/2026

Yamaha CR-2020 ready for cleaning and restoration!

Becker Europa TR car radio from a 1967 Mercedes back up and running again. Had many open and high ESR capacitors. Repla...
04/02/2026

Becker Europa TR car radio from a 1967 Mercedes back up and running again. Had many open and high ESR capacitors. Replaced all the electrolytics. Cleaned up the dial face and k***s. Added some paint to the dial indicator.

These Heathkit W4-AM amplifiers went to their owner with Dave Gilespie designed EL34 mods. Removed all old circuits, c...
04/01/2026

These Heathkit W4-AM amplifiers went to their owner with Dave Gilespie designed EL34 mods. Removed all old circuits, cleaned and polished the chassis, sanded and painted the OPT and choke, machined new switch and lamp holders. Built a bucking transformer. All new components.

Looking and sounding great!

Had a short between two inner ground planes on a circuit board. 8 Amps did not fuse it open, but it did reveal a warm s...
02/27/2026

Had a short between two inner ground planes on a circuit board. 8 Amps did not fuse it open, but it did reveal a warm spot. Milled down 0.004" to reveal the ground planes and the short!

Pioneer SX-850 Restoration:Findings: Power cord has been spliced. AM bar antenna missing. One bottom cover screw is mis...
02/03/2026

Pioneer SX-850 Restoration:

Findings: Power cord has been spliced. AM bar antenna missing. One bottom cover screw is
missing. Left and right DC offset is unstable
and tripping protection circuit (relay clicking
on/off). Q1-Q4 are bad on output amplifiers. All lamps are working (dial, indicator and stereo). Power supply Q3 & Q5 previously replaced with 2SC484 & RCA SK3020. –19V supply is not working (Q6 and C23 are bad). Q1-Q6 and C7 and C8 of equalizer amplifier are bad. Left auxiliary input is not working. Function switches are intermittant and need to be dis-assembled for cleaning and servicing. All transistor heatsinks need new thermal compound (dried). Relay contacts are intermittant (needs replacing). Main filter caps measure half of rated value. AM and FM need alignment.

REPAIRS: Replaced power cord. Replaced AM bar antenna. Replaced Q1-Q4 on output amplifiers with gain matched KSA992
transistors. Calibrated DC offset and current bias. DC offset is now stable and relay does not click on/off. Replaced Q6 and
C23. –19V supply is now working. Equalizer amp: replaced Q1 & Q2 with gain matched KSA992s, replaced Q3-Q6 with KAC1845,
replaced C7 & C8. Equalizer amp is now working. Removed function switch pcb, dis-assembled each switch, cleaned and
polished and applied G100. Function switches are now working good.

RESTORATION: Washed and dried entire unit. Replaced all electrolytic capacitors with MKS2,FR,FC,UKL. Re-stuffed main filter caps with 15000uf/50V. Power supply replaced Q3,Q7 with KSC2383,Q5 with KSC2690. Protection unit replaced Q7 with KSC2690, added 1N4004 to pins 9 & 10. Replaced all “black leg” transistors (2SC869,2SC1312,2SC1313,2SA725,2SA726) with KSC1845 and KSA992 transistors. Replaced protection relay. Replaced bias and offset pots with Bourns 25 turn. Replaced dial lamps with warm white LED and all function, stereo and speaker with 8V/50mA/4mm lamps. Replaced all heatsinks’ thermal compound. Applied D5/G5 to all switches, D100/G100 to all inputs and outputs, D5/F5 to all control pots. Calibrated bias and offset.
Aligned AM and FM bands. Cleaned and polished front face and k***s. Applied Howards-Restore-A-Finish to wood. Verified all inputs and outputs. Outputs produce 72W into 8ohms at 1Khz (rated at 65W). Ran unit for 8 hours with no problems observed.

Replacing a selenium rectifier with 1N4007 full wave bridge using the same package.
01/20/2026

Replacing a selenium rectifier with 1N4007 full wave bridge using the same package.

Restored a Harmon Kardon HK-730 ReceiverFindings: Cover, dial, k***s etc are dirty. Internally lots of dirt and dust. Al...
01/08/2026

Restored a Harmon Kardon HK-730 Receiver

Findings: Cover, dial, k***s etc are dirty.
Internally lots of dirt and dust. All dial
lamps, pointer and stereo lamps are burnt out.
Volume and balance pots are very scratchy.
Output transistor thermal grease has dried. As found offset L= -21mV, R= +26mV.

Service Performed-
Partially dis-assembled for cleaning. Wash and dried entire unit.

Replaced all electrolytic capacitors. Replaced twelve 2SC1345 transistors with KSC1845 (Tone/Preamp, Equalizer, Mode/Control). Replaced six 2SC1400 transistors including matching differential input pairs with KSC1845(Power Amps).

Applied D5/G5 to all switches, inputs and outputs. Applied D5/F5 to all control pots.

Replaced thermal grease on all heatsinks. Cleaned and polished front face and k***s. Replaced all lamps.

Calibrated bias. Verified all operations, inputs and outputs. As left offset L=-16mV R=-16mV. As left power output 46Watts/channel into 8ohms (40Watts/ch spec).

Finished a restoration of a Marantz 2265 Receiver. Just a beautiful looking unit. See the full report in last picture. ...
12/05/2025

Finished a restoration of a Marantz 2265 Receiver. Just a beautiful looking unit. See the full report in last picture.

Service Performed-
Washed and dried entire unit. Dis-assembled unit to gain access to control pots, switches and PCB boards. Cleaned and polished front face and k***s. Cleaned and polished front clear dial. Re-glued front face parts and clear dial in place. Glued paper insulator in place on bottom cover.

Machined a replacement balance k**b holder and installed a new balance k**b. Epoxied plastic screw holder of lamp holder assembly. Removed anttenna connector assembly and repaired AM connector.

Replaced all electrolytic capacitors (FR, FC, UKL, MKS2). Replaced four 2SC1344 transistors in phono stage with KSC1845. Replaced output protection relay(MY2).

Replaced offset and bias adjustment pots
with bourns 25 turn. Replaced all lamps. Replaced vellum paper (48 #) for dial and meters. Applied D5/F5 to all control pots. Applied D5/G5 to all inputs, outputs and switches. Applied new thermal grease to
output and power supply transistors.

Calibrated bias and offset to specifications. Replaced dubbing and headphone jacks. Aligned FM tuning. FM now goes into STEREO mode. Verified all inputs and outputs using sine and square waves.

Both channels output is 70watts (65W rated). Ran unit for four hours with no problems observed.

Finished a partial restoration of a Marantz 7 preamplifier.
12/01/2025

Finished a partial restoration of a Marantz 7 preamplifier.

Replacing vellum paper on a Marantz 2265 receiver. 48 #/180gsm.
12/01/2025

Replacing vellum paper on a Marantz 2265 receiver. 48 #/180gsm.

Akai GX-635D auto-reverse switches dis-assembly and clean.
10/16/2025

Akai GX-635D auto-reverse switches dis-assembly and clean.

Address

Eau Claire, WI

Telephone

+16123619949

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