We have introduced more new valves which are all now in stock. We now have the more specialised valves that are used in Ampeg and Peavey guitar amps. The Electro Harmonix 12DW7 ( also known as the ECC832) is a double triode and in this valve one half is like an ECC83 ( 12 AX7) with a gain of 100 and the other half like an ECC82 ( 12AU7) with a gain of 20. Peavey
Note: We now have a new, superior solution to Marshall JCM2000 bias drift issues. Find the details here. I have now worked on two Marshall JCM2000 amps and both are around 10 years old. Both had very similar faults. The fault on both was that the amps sounded “rubbish” and both were cooking the EL34 output valves. Instead of running at about 45 mA of bias current the lowest adjustment you could achieve was over
A really neat added value benefit of using Tung Sol valves in your amp is their low microphonics. During testing at the factory Tung Sol Valves are tested on a vibrating table to ensure they are not microphonic. Of course this extra testing adds a little bit to the cost. I first witnessed this benefit in my own original silverface Fender amp. Ever since it was new way back in 1970 the amp was always
Why did that valve suddenly stop working? I thought it might be useful to look at what the common failures in valves are as they age. I have had a number of folks ask me why their amp suddenly started blowing fuses. My first recommendation is to replace the fuse , unplug the valve rectifier and see if it still blowing fuses. More often than not, the amp stops blowing fuses when the rectifier is
~EL84 ( 6BQ5) This blog article is about how to get a clean sounding amp and excellent hifi performance. The ideal valve for the hifi amp is one that has low distortion, excellent power handling and a long life. The ideal output valve for the guitar player that likes the ultimate in clean sound also needs the same characteristics. If your amp uses the EL84 ( US number 6BQ5), then please read more……. Hi-Fi amps
Over the weekend, I got my hands on a bunch of vintage audio valves and rectifiers. I went through all of them and tested them and that blew most of my weekend. Testing valves and doing matching is a boring but very necessary job! Some were brand new in boxes, some were loose in Tupperware containers and obviously had been used. I was curious also to see the test results of vintage versus new valves
