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
Having done a long term test on a JJ Electronic 6L6, and saw that the cathode current remained rock solid over over a period of 48 hours the next valve to be tested was the EL84. The reason for running the valves from new over a period of many hours was to see if burn in provided any advantage when doing matching. EL84’s are used in many amps such as the Fender Blues Jr, LazyZ
EL84 To Burn in or not to burn in that is the question Read More »
A number of valve sellers offer output valves that are “burned in”. Burning in valves means basically running them for a number of hours. It is claimed that the benefit is that this weeds out the ” weak valves” and improves the matching of the valves as the implication is that the valves go out of matching if they are matched from new. I was suspicious of this claim as there is no data produced
A new valve has entered production. The JJ Electronic 12BH7-A has been introduced. It has been in development for a good number of months and now first production is being released. One other supplier has been making new 12BH7’s but were always difficult to get into stock. So the JJ electronic 12BH7 -A version is a welcome addition from a trusted European valve manufacturer. We are official authorised dealers for JJ Electronic. We have the
JJ Electronic 12BH7-A Brand New Valve from JJ Electronic ! Read More »
I received an Orange Tiny Terror for repair. It had lost its voice ! I had never worked one of these amps so an exciting new experience. It is built into a nice metal case and is a very conventional circuit using two ECC83’s and two EL84’s in the output. Here is a picture of the amp opened up and the picture below shows the printed circuit board construction. I found it quite funny to
A Marshall JCM900 amp arrived. The JCM900 combo is basically a 100 watt twin 12 inch speaker combo and is a true Marshall stack in a matchbox. Nice and easy to transport. When new these amps supplied in two variants, with one having 4x EL34’s in the output and the other variant having slightly lower power with 4x 5881’s. This amp was dead. Zero output and a lovely hum. Inside the amp proudly displayed
