A Laney VH100R amp head came in for a service. Â While “nothing” was wrong with it, the owner decided just to have its health checked out. This is a really high gain amp with 6 ECC83/12AX7 pre-amp valves driving 4x EL34B to give a 100 watts out. On switch on it was clear that a couple of the pre-amp valves had gone microphonic and the bases of the EL34B were all burnt. A sign of […]
As its a new year I thought I should share links of interesting folks who you could find useful. Juke Box Genius This is nice guy who is based in Bristol and he travels to customers and fixes jukeboxes. Â He does all the mechanical and electrical servicing and total restorations too. The Juke Box Man Continuing the juke box theme, here is a site where you can find all those important bits to keep your
Many folks ask what the difference is between the standard EL84 and the more expensive Sovtek EL84M. There has been no data available and I see lots of questions on forums etc asking about where you can get a data sheet. I worked with the Sovtek team and pulled a product information sheet together out of Russian documents etc. First of all here is some background info as to why this was done The EL84
Sovtek EL84M More Headroom More Power Longer Life Read More »
A Fender Supersonic 60 arrived as it plainly liked to sing is own praises- when the volume was turned up it howled like a banshee! The issue was that the amp was totally microphonic. It would work at lower volumes but started howling at higher volumes The Fender Supersonic is a  complex design for a 60 watt amp. It has 10 valves, comprising of 2 x ECC81 ( 12AT7), 6x ECC83 ( 12AX7), and 2x
Following our blog on testing the 6L6 and the El84, we have now done a burn test on a JJ El34. Â The test got delayed as our Avo Mk2 tester developed a fault with a worn out “backing off” Â pot and I had to come up with a good repair not having the benefit of any replacement part. I guess this part has not been made since the days of Harold Wilson being Prime Minister
I was curious to see if there was any information on the net regarding the noise figures for any noise measurements on preamp valves Noise is just one of the many things to look at in selecting a good valve for your amp and I thought it was worth taking a look at this. Noise measurements on pre-amp valves  requires building some specialist test gear so I thought I do some research to find information.
Here is a guide to Pre-amp Valves There are many types of pre-amps around all with the same pinout and if you are not a valve geek like me then how do you work out what is best for you? I had a nice customer highlight this to me and I thought it would be useful to make some notes which may help you choose the right pre-amp valve especially for the V1 position in