Repairs Book Closed Till September


I have reluctantly taken the decision to close my repairs book until September 2017. I am doing this for a few reasons:

  • I have a few repair jobs backed up at the moment that I need to clear before I take in any more and a couple of on site PAT testing jobs to do.
  • I am considering moving into building valve amplifiers and will investigate some other electronic business ideas I have and I need to commit some time to this and build a few prototypes.
  • I have a more advanced valve tester half built that needs to be finished.
  • I plan to reorganise my stock of parts and build some better storage shelving.
  • I have to help my father move house and get his existing house in Sheffield ready for sale.

I am sorry if my customers are stuck with faulty gear but I think it is better to do this than promise to fix stuff then let folks down.

I will still be checking my email (the best way to contact me with enquiries in the mean time) if you have any questions or enquiries.

Bye for now!
Dan Davenport.


Recent Repairs: Trace Elliot Bonneville C50

Trace Elliot Bonneville

James Horrocks is the bass player in the Lol Goodman Band a top class blues band that can be seen at blues venues and festivals around the UK. He called in with a Trace Elliot Boneville C50 1×12 lead combo. It was sounding rubbish, kept cutting out and the reverb was weak and had a hiss. It needed a new pair of EL34 output tubes and some fresh resistors in the reverb circuit. I have never encountered one of these before. It is unusual in that it has two foot switchable channels but volume level is the only parameter you can set independently. The GAIN control and PREAMP STYLE are common to both. Also, it has an FX loop switch on the front panel that cuts off the guitar signal completely when the rear FX LOOP switch is set to SERIES. I thought this was a fault at first but when I looked at the circuit, it was designed this way. The FX OFF switch works as expected when the rear switch is in PARALLEL mode. Despite it’s quirks, it sounds and looks good, especially if you’re into motorbikes. Like the green tolex too.

James said: “Amp sound great Dan …. good job well done :)”

Cheers James!

Lol Goodman Band

Fullscreen capture 11052017 093336

SOLD: Fender Bassman 6G6-B 1964 Head and Cab

IMG_20160520_094742SOLD: 1964 Fender Bassman 50 Watt Head and 2×12 Speaker Cab.

Manufactured: 1964

Covering: Rough blonde Tolex

Grille: Recovered with new gold thread grille cloth.


IMG_20160520_094852Pre-amp and PI: 4x ECC83/12AX7 Mixed Fender and one new JJ

Power amp: 2x brand new Sovtek 5881WXT

Rectifier: Original solid state diodes

Mains supply: The original mains power transformer must have been replaced because the back of the chassis specifies US voltage. It is an original 1964 Fender export model 240 Volts 125P7DX.

Output transformer: Fender 1964 125A13A.

Choke: 1964 model:125C1A

Power output: 50 Watts into 4 Ohms

IMG_1898 IMG_1899Speakers: 2x 12” 8 Ohms wired in parallel = 4 Ohms

1x Oxford 12MGX

1x Utah Electronics

All in good working order.

IMG_20160520_094713The rear amplifier cover is missing. A matching blonde Tolex replacement can be supplied if required at extra cost. The thumbscrews that lock head and speaker cab and the side props are missing. They are still available from Fender but are quite expensive for what they are. There are some of the usual marks and scuffs on the Tolex.


The main HT smoothing capacitors have been replaced at some point but the pre-amp smoothing caps are original. They still test OK. I replaced the smoothing capacitor on the bias circuit and the screen grid power resistors. The output tubes are new as is the V3 pre-amp tube.

For more information “try outs” & viewing, please contact Dan at LaLuna Technology

Phone: 01457 597018

Peavey UL-12 Satellite PA Speakers – Schematic

I had a pair of Peavey UL-12 speakers in for repair from Barry Barnes of the band Sinnerboy, the excellent Rory Gallagher tribute. (See The recently re-established Peavey UK distributor were taking ages to get me some replacement Black Widow baskets so I ended up cancelling the order and getting them reconed at RMJ in Keighley. I sketched out a schematic for the crossover (I have just included the passive setup. There is an alternative connector for active).

Peavey UL-12 PA speaker schematic - passive

Peavey UL-12 PA speaker schematic – passive

The tweeter fuse is a polyswitch or resettable fuse which I replaced with TE Connectivity RXEF040 which opens the circuit at about 400 mA RMS and dissipates excess energy in the 2.5 Ohm resistors and the bulb. The fuses had exploded in a puff of soot which I am sure isn’t meant to happen. The tweeter coils were intact though.

Latest Repairs: Fender Rhodes 54 Electric Piano

IMG_1882I had a Fender Rhodes 54 key electric piano in for repair last month. They use guitar type magnetic pickups wired together. If one pickup fails, every key goes silent. It is still easy to get spare parts for these so they can be brought back to top condition. The 73 or 88 key versions are more popular than this 1980 vintage 54 key instrument. I repaired or replaced 17 pickups on this one, re-adjusted the hammer action and individual note volume and re-tuned. IMG_1876 IMG_1875Call me if you have one needs some attention.

Watkins (WEM) Copicat IC300 tape delay and echo


WEM Copicat IC300. All it needed was head cleaning and a new tape.

WEM Copicat IC300. All it needed was head cleaning and a new tape.

WEM Copicat IC300 insides.

WEM Copicat IC300. All it needed was head cleaning and a new tape.

One of my regulars brought this in. He bought it for partly nostalgic reasons. It was in pretty good nick. All I did was PAT test, clean heads and change tape. The original send/return jack on this model is a 3 pole stereo TRS jack like an insert jack on a mixer channel. The extra, non standard jack next to it had been wired to the playback head mix. From here you got the echoes without the original. Presumably the owner wanted a tape delay for some reason. There was a bit of flutter from the direct drive induction motor but it kind of adds to the character of the effect. For a circuit that uses all 741 op-amps it had very little background hiss. Nice bit of vintage gear.

SOLD: Pearl DS-06 Distortion Pedal

The Effects Freak website says:
“The vintage Pearl Distortion DS-06 made in Japan (1980s). It has a six way selector for spectrum mode, this is like a parametric EQ for different tonal variations, different sonically than your basic tone knobs. A level to vary the amount of this EQ in the signal — then a separate out level and a control knob for the amount of distortion, very versatile pedal for its day and now for that matter.”

“Great distortion unit from the 80s. These Pearl pedals are top quality. The Spectrum part of the pedal has a six function rotary knob which provides for a variety of tones. Very similar to the Rat on one setting and like the Boss DS-1 on another.”

Includes new 9V battery. Can be mains adapter powered, 9V centre -ve.
Fully tested and working.
Contact me to arrange a try out.

£40 + 3.50 P&P