Okay so I relented and worked on an amp with not one single lonely valve/ tube inside. Time to fix a Trace Elliot GP7SM bass amp. I will have therapy to overcome this valveless trauma. I agreed to work on this amp for a nice customer because it had suffered mechanical damage. A relatively easy repair. It lead to me discovering a bit of amp archeology that I thought I would share. I found it […]
Our task was to renovate a June 1973 Marshall Model 1959 Super Lead 100 watt head It had been modified in the 1990’s to use 5881 output valves. This was the time when good quality EL34’s were difficult to source. JCM900’s were using 5881’s in production. A master volume had been added too. The amp had been stored in a garage for 15- 20y ears so it was not a smart plan to switch it
We now own the trademark ” Zaerix” name along with the logo. Zaerix is an old name in the UK market. We are working to bring the brand back to life while upholding the values of this famous name from the past.. Zaerix was the brand name of a company called Z and I Aero Services. They did not make valves themselves but they did source high quality valves from manufacturers around the world and
It is common design practice overrunning output valves. It is done with all types . There are some amps that use EL34’s and run them way over 500 volts. This is well above and beyond the maximum ratings of certain manufacturers. It is inviting trouble as the valves age, they have the possibility of flashing over and failing. We see similar effects with EL84’s. This is not a new phenomenon. Amp companies have been doing
Many amps have a valve rectifier valve. Typical types are EZ81, 5Y3, GZ34/5AR4 and 5U4. There are variations on the letters at the end of the part number but the basic part number product will do the job. The alternative is to use solid state diodes. So why have a less reliable valve/tube rectifier than modern diodes? rectifier is just the old name for a diode. How do you know when your rectifier valve needs
Find the valves you need quick and easy We have added new categories to make it easier finding valves/ tubes . If you go to the ” Categories “ menu at the top of the page you find instant links to common types. The idea being to find stuff faster. If you are looking for more unusual pre-amps such as the 12DW7 or ECC99 they are still there just look in the “preamp valves” section
A Peavey Classic 30 Restoration was undertaken. Initially it was taken in for just a repair. It had sat in a garage for many years. There was rust on the face plate so a good indication dampness had got to the amp too. The amp had been switched on by the owner and it was totally dead. Having gone through the amp I can now provide details of the autopsy. The electrolytic capacitors in the