Tube Amp Archive

Will do, expecting components next day or two, Cheers.

with oscillator tube out, lower ?= 0.078 VDC, upper ?= 0.007 VDC

with the - probe on the chassis, first ? I get 170VDC, 2nd ? I get it switching between 27 VDC and -OL

The amp label asks for 110v, schematic states voltages +/- 20% IMG_1238.jpeg Measured from chassis ground to the point marked by red dot, 172 VDC, from dot to 1st capacitor leg, 124 VDC, from 1st leg to 2nd leg, 0.973 VDC, from 2nd leg to 3rd leg, 1.3 VDC IMG_1239.jpeg Measured from chassis ground t...

I'm getting 4.64k there. And having checked again the cathode is exactly 3.5vdc. I'm running the amp at exactly 110 vac, getting 432vdc on the 5881 plates. Going right to left in the images the caps read as follows measured in circuit without lifting leg. ASTRONS .05 outer foil= 60v, 300v .02 outer ...

I'm awaiting delivery of replacement components right now, not changed anything out as yet.

Hi Martin, Many thanks for your response, measured resistor values are in red in attachment, voltage readings are as follows as per your recommendation, V3 triode A plate 140 vdc grid 0 vdc cathode 1.5 vdc V3 triode B plate 295 vdc grid 140 vdc cathode 1.5 vdc V4 triode A plate 0 vdc grid 0 vdc cath...

I've sorted the power cord and secured the earth bond with some loctite thread locker adhesive. Amp sounds good though the Harmonic Tremolo is a little underwhelming, weak, has to be at max intensity and volume around 6/7 to really hear it at all, I've subbed in several known good strong tubes in V3...

Thanks, and I hear what you are saying, but I'm not going to be drilling any holes in the amp, plus that was the site of the original earthing/death cap,now removed, the connection is soldered ,crimped, shrink tubed and taped, well tightened down. I'll be checking it over regularly and it won't be g...

Copy that on the power cord, outer casing is caught right on the grommet, was a struggle using the original, the splice is twisted horizontally, soldered,tube shrinked and taped. Apologies to the purists but I spliced new components in, J hooked then soldered, I'm not confident enough in my solderin...

Just now at the powering up via the current limiter stage, posting shots of the Bias circuit and 3 prong power connections before doing so.

Thanks I'll try them.

HI, yes I hear you on that, but the US plugs /recepticles are not readily available here from what I can see.

Current limiter not so easy to procure here in the UK, Kendrick amps make one, looks the business, but it's $139 before shipping and our wonderful 20-23% sales tax and I'd still have to find a 120v 100w tungsten filament lamp. Is there another method I could use?

Sorry, no not working yet, got to get a current limiter sorted out.