The Amp Garage

KT45's have been out of production a long time and could be found on for sale pages. There are differences between the EL34 and 6L6 tubes of course but not that much. Hi Mark (and Jamie). KT is still going, just a slow mover. Pearler of an amp. 6545 is the out of production KT45 cousin. I'll have a...

But switching aside, I must say, I do like those milkman aesthetics. And I'm a sucker for a nice 15" speaker.

There is really no reason to have a standby switch!! The attached is from a couple of very knowledgeable tube guys and they pretty much say the same thing. a'doc Good info. I've enjoyed reading Merlins books and have subsequently stopped using the standby's on my amps, both ss and tube recs, and it...

Thanks guys. Exactly what I wanted to know.

I have done a fair bit of reading/browsing so far, but sometimes I just want a definitive answer to what often appears to be assumed knowledge. Manual seems to be very good none the less.

And that tiger was frightening

I'm looking at an old second hand HP 54600A or 54601A locally on ebay. Reading the manual they have a max voltage of 400 dc+ac peak. Having not owned or used an oscilloscope before, does this mean that if I am using the 10x probes, when reading from a 500v source the oscilloscope is seeing 50v? For ...

Maybe start with a really nice head cabinet. I've never made a speaker cab or head cab out of hardwood (but I have made other stuff with it). My cab have been always been solid pine or marine (voidless) ply. But looking at all of those trainwreck heads I think it would be a real nice project. I've h...

Best thing is you won't do the same thing again next time.......or if you are like me, it won't take as long to work out next time.......

With the ef86 front end, maybe try the 66 caps in the tone stack (1000pF instead of 250 and .01uF instead of .022). I'd be interested to do the specific math, but the 66 is a much less trebly amp than either the z28 or kt45. But as both channels are bright....... I don't have those answers at my fin...

I've got some nice light colored, high quality grill cloth that will look similar to what it apparently came out with 70 years ago. Joined radiomuseum.org just so I can get more information on some of the old tubes. Most seem to have been common in old car radios, and other radios. 7a7 pentode front...

In the schematic I've tried to get a few things to match the actual wiring pattern rather than being the neatest, especially with the 7a7. I'll come back to it next week and have another go at making a prettier one.

Schematic and 1 more pic.

Picked this up recently for $150. Hasn't worked for 10 years apparently when it was brought to australia and damaged in transit. So far all I've done is pull it open and am working on the schematic and learning about the tubes and field coil speaker. As I go through I will be asking specific questio...

Finally had a go at some ef86 load lines (it's been over a month). Not sure if it is of much use to you at this stage, but it was a good learning experience (and I'm not even sure how correct they are). Spent a lot of time measuring voltages and doing lots of sums and scratching my head. Surprised h...

+1 on Merlins books. I've also wondered about the Oconner books but haven't gone there yet.

And don't give up on the KT66s yet.