Dr Z Repair – Mini Z

Dr Z Repair

Dr Z Repair – Mini Z

This Dr Z Repair was a simple job. This DR Z amp is a 2 valve class A amp with one ECC83/12AX7 and one EL84. In this case, the output EL84 valve was faulty, the heater.

The customer asked me to replace the amp with one the fancy ‘cryo’ frozen valves from Harma. I’m not entirely sure if this changes the amp’s tone or just makes Princess Leia fancy it. Maybe if you’ve tried one, you could let me know!

This repair was easily finished within the diagnostic period. When I find a quick fix for customer’s amps I always perform a routine ‘mini service’ to ensure the customer gets their money’s worth.

If you have a Dr Z Repair job that needs doing please, get in touch.

Marshall Repair – JCM2000 DSL100

Marshall Repair

This Marshall Repair was brought to me with one of those sneaky ‘hard to find’ problems. The amp was blowing fuses when the customer was playing it. He’d taken the amp to another repairer who hadn’t found any problems. Unfortunately the amp continued to blow fuses.

Guitar amplifier repairs of this kind often have to be treated in a different way. After an initial examination, opening up the amp and checking for any burnt components or loose joints I placed the amplifier on soak test. This involves playing a representative signal through the amp into a dummy load in the conditions that the amp was in when it was blowing fuses. During this soak test I observed that under certain conditions one of the power valves was sparking internally. I swapped the set of valves, re-biased and then placed the amp back on soak test. Since the amp wasn’t blowing fuses or sparking any longer, I decided that it was ready to go.

If you have a Marshall repair job that needs doing, please get in touch via the contact page.

Laney Repair – VC50

Laney Repair

Laney Repair

This Laney Repair was a mixed bag of several issues! The amp is a VC50 – 5 12AX7 valves and 2 6L6s in the output. This particular specimen has a strange an whine present whenever channel A’s spring reverb was used, also a faulty gain control on channel A, an intermittently working footswitch and a rather noisy pre-amp stage.

Since the amp is old and worth under £300 in used condition I advised the customer that an in depth repair might not be in his best financial interests. We agreed a price limit, within which I was able to fix the faulty gain knob, the reverb oscillation and the intermittent switch. This then allowed the customer to sell the amp in working condition and he put the money towards a new amp that suited his purposes more closely. Everyone was happy!

Forgot to photograph this one – apologies for the stock image!

If you have a Laney repair job that needs doing, please get in touch via the contact page.