Yamaha C-4 Preamplifier Input Knob Selector Repair

Repair of KUSTOM KBA 100 Bass Guitar Amplifier TDA7293 100W

Kustom KBA 100 fix.
Transformer and TDA7293 IC Audio Power Amplifier  Replacement.

Sony Esprit TA-E901 Preamplifier Audio Module Replacement, Substitute, Spare revision 1

My own project about Sony Audio Module 
Amplifier board for Sony ESPRIT repair.
TA-E901 Flat Amp Preamplifier 

Sony CDP-X7ESD CD Player restoration KSS-190AFailure DIY Repair Fix

High End CD Palyer, Sony ES series, CDP-X7ESD with broken Optical Group KSS-190A

No Focus and No Tracking Lent's movement on CD insertion.

I found the flat cable broken.

Some pictures about my  work:

KSS-190A

KSS-190A  Broken Kapton Flat Cable on 90° corner 

KSS-190A

KSS-190A

KSS-190A

Workig CD Player

11

Sony Cassette Deck ES 3Heads Closed Loop Dual Capstan

Cassette Deck and analog sound passion!!!
A little dream has been realized:  my Sony TC-K777es and his little sister Sony TC-K666es !

Sony TC K777es Sony TC K666es

Sony TC K777es Sony TC K666es

Ampeg SVT3 Pro Tube & Mosfet Electric Bass Amplifier - Bias Adj and Repair

DIY DC/DC Dual Boost regulated Power Supply for High Voltage Tube VAS

In relation to DIY Hybrid amplifer the first step is to obtain the High Voltage for tube's anode supply and the low voltage for heaters.

Sometimes, if not always, fora a 100W amplifier you have a double sec 150-300VA  36-0-36Vac power transformer only.
Using this board you can adjust the  needed voltage for tube stage starting from your transformer.
Without use any voltage doubler and linear regulators.

The Following image shows how the Double Boost works.

From unregulated  +55/0/-55Vdc the circuit gives at his output the needed voltage, able to supply the anode current for a tube stage.

For example you can obtain +90/0/-90Vdc and 6.3Vdc for the heaters..

Gem Super Deluxe 20 Tube Guitar Amplifier Push Pull 6L6 12AX7 driver

New Vacuum Tubes for GEM Super Deluxe 20, great 60's italian guitar amplifier
Sovtek Matched Pair 6L6 power tubes and 3 x 12AX7 for 20W

Point to point old stile  mounting

6L6 matched pair and 12AX7

Sony PS-X65 DD Turntable Repaired Restored

Sony PS-X65, trouble of drop point solved.
IC103 defective, once replaced the turntable plays well!!

Signals on pin 1 and 4 weren't correct, Luckily t was only the 4069 IC...

Faulty Component, datacode 79 48

My replacement..NOS MC14069UB datacode 80 36

Sony PS-X65 DD Turntable Quartz X TAL-LOCK System Full Electronic Microprocessor Controlled Magnetic Tracking

My New entry, not working, turntable Sony PS-X65 substitue of other Sony Direct Drive Turntable

 Sony PS-X60. Only better S/N ratio for the specs, but it has more charm.

Speed is correct and Locked, both 33 1/3 and 45 rpm, in manual play it's perfect only a little trouble on the mute switch, easily solved.

In automatic play tonearm doesn't stop and doesn't retun to stop position...

Quartz X TAL-LOCK SYSTEM

It Spinning well!

It look so beautifull..

Automatic actions are guarantee by 2  electronic controlled motors, no mechanicals devices like his predecessor, PS-X60.
The Horizontal motor is used also for the correct Traking Force

There are 2 coaxial "brushless" motors: one for the lift the other,
you can see the coils, for the Horizontal Movement