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
A Marshall JCM900 Breaking Valves was the cause of this amp’s failure. It travels around a lot and it has the original 1990’s valve retainers on the output valves. The original ones fitted to this 4102 model are shown below. These are fitted over the 5881’s to hold them in place. The issue is that an amp is well gigged and in and out of vans suffers a lot of vibration. These holders rub on
 Quick Intro to the Fender Bassbreaker 007 The Fender Bassbreaker 007 is a cute little valve amp. There are two versions – a head and a combo. It has two 12AX7 pre-amp valves and one EL84 output valve. It has a 10 inch Celestion speaker. A nice compact practice amp. Check it out on the Fender website. Fender quotes this amp as 7 watts audio output in the manual. It does not say whether