I use a thermionic valve (or vacuum tube) tester based on the excellent uTracer 3 circuit board designed and supplied as a kit by the Dutch wife and husband partnership Marie-José den Brok and Ronald Dekker. See https://www.dos4ever.com/uTracer3/uTracer3_pag0.html
Here Jennie Nell with her Kawai MP6 stage piano. It had a blown -15 Volt regulator on the internal power supply board. Nice keyboard to work on, easy to disassemble. It all powered up and showed a display because the main logic board was powered but there was no audio signal from the output jacks or headphones. It is all fixed now.
Jennie plays keys for Kieran Dobson & The State and solo as Nell
This is the prettiest flight case I have ever had in my shop!
LaLuna Technology now accepts three payment methods.
Bank transfer with internet banking (BACS). This is my preferred method.
Credit or debit card.
Trace Elliot manufacturing, what were you thinking?! Expensive looking collet knobs on splined potentiometer shafts. They didn’t even put little shims in the slots as I have seen some manufacturers do so the slot closes up. The knobs just go on wonky and come loose so you would be paying for this lazy solution when the warranty claims start rolling in.
By the way folks. Don’t ever try to prise the slot apart, the metal breaks so easily and you end up paying for a new potentiometer. The only technique I found to get them to stay on was to give them a really good tighten with a good driver and hope for the best.
This straight-up, no nonsense 160 watt bass combo features a 15″ custom celestion speaker, bass, treble and 7 band graphic mid, switchable compressor and switchable limiter in a solid cabinet with top and side handles.
Power RMS 160 Watts
Inputs Normal & High
Equalisation Bass, Treble and 7 Band Graphic Mid
Speaker connections 1x Jack (4 Ohms External)
Drivers 1×15″ Custom Celestion
DI Socket : Pre EQ XLR
Kick Proof Metal Grill
Weight 25.25 Kg
Dimensions (cm) 57.8 x 50.5 x 33.5
The 40 Hz graphic equaliser slider has snapped off short but can still be moved and works OK.
Model: Quad 65 DFX
Power output: 65 Watts RMS
Channels: Rhythm Neutral/Brilliant, Lead UK/USA
Effects: 8 x preset
Impedance: 8 Ω
Internal speaker: Celestion Seventy 80. 80 Watt RMS 8 Ω
Dimensions: 46 x 53 x 29.5 cm
XLR DI output
CD/AUX input summing stereo jack
FX Loop send/Return
Footswitch Jack (footswitch not included)
Amp is very tidy and has just been recovered with leather effect vinyl.
200 Watts 8 Ohms
Parallel Speakon and 1/4 inch jack sockets.
Celestion G15Z 200 15 inch Driver
71 x 32 x 79 cm
Newly re-covered with leather effect vinyl and rewired
Self built one off
The laney TT100 service manual does not give a simple layout diagram to show which valve is which and what it does so I have posted one here. Click image for bigger picture. For the schematics see here: laney_tt100_sch
The Fradan Echomatic 50. Tape delay and 50 Watt valve amp in one box. Delivers 50 Watts RMS into 8 Ohms. The two output jacks are paralleled for 2 x 16 Ohm cabinets if desired.
Here is how you wire the footswitch on the Fradan Echomatic 50
Put the switch between pin 1 and pin 3 and an indicator bulb (6.3V AC) between pin 1 and pin 2. There is 6.3V from the valve heater supply between pin 2 and pin 3 so don’t short those pins or you will blow the internal fuse.
I had to repair a Gibson Les Paul boost circuit and drew out the diagram which does not seem to be available on the net so I thought I’d share. The 47k trimmer sets the boost gain. The 4.7pF caps are an educated guess. I think they are just there to avoid RF interference. It was odd but the source terminal of the J202 FET was connected to the 22k load resistor R3. I guess they are interchangeable.
Gibson Les Paul Boost Circuit