The Amp Garage

I had some squealing on an 18 watt Superlite that ended up being the output of the master volume. Play with the lead out of the master volume to the phase inverter ... is this lead a shielded lead? --==-- As far as the noise on V1 and not on the other tubes ... V1 is the most sensitive tube as it's ...

CT is center tap

I built a sort-of 5E3 using 6K6's ... the plate voltages were just over 300V, 6K6's are pentodes, so they are a bit different sounding than 6V6's I did a bunch of OT swapping and ended up using a 6.6k MPS OT at double impedance 8 ohm load into the 4 ohm tap ... It's a sweet little amp ... one friend...

A 'Log B' pot in TSC is a 10% Audio taper ... I think CTS Audio pots measure pretty close to 10% ... Alpha's tend to be closer to 15%

It seems to me that 403V on the 6L6 plate is high for a 275v-0v-275V PT ???

The zener was 6V originally for low powered amps 5 watt or so ... it was changed to 12V so it would work with higher wattage amps

Thanks again for the help, all. I look for an 8K primary OT. The board should be mounted from the "ceiling" with the bottom plate being toward the floor and the cage on "top" of the chassis. That actually is a really good point, though, that I might not have thought of. How well does a sag resistor...

I used a 300V 150mA non-center tapped PT for the ss diode rectified (with 100 ohm sag resistor) 5E3 I built for a friend.
It ended up at around 360-370V actual plate voltage (plate minus cathode)

The 1760H is more like a Deluxe Reverb OT (6.6k) than a 5E3 OT (8k)

All of the control leads can be sensitive ... One Superlite I built had a lot of instability issues until I changed out one lead and moved others around a bit ... The 820 ohm cathode on the second preamp triode is to try to make up for some of the gain lost to the plate driven tone stack. The first ...

rj ... I have one of the JetCity 20 watt combos with the (china) Eminence speakers and the speaker is ~ok~ not the greatest but not junk either ... It's a similar speaker to the Epiphone Lady Luck ... I only use them with low wattage amps also 15 to 20 watts It sounds to me like your speaker is bad ...

As far as being dark and to dirty ... what are your preamp voltages?

Too low of preamp voltages and the amp will be dark and too dirty

A "standard" 18 watt Marshall is a cathode biased amp with no NFB (negative feedback) ... without NFB an amp is "wilder" A 45/50 or 100 watt Marshall is a fixed bias amp with NFB. NFB cleans up and controls the output section of the amp ... in doing so NFB "flattens" the tone, a presence control let...

Plug a patch cable into the fx loop in/out

The cap value depends on the grid reference resistor values ... Vox uses 220k's and a 0.0047uf cap in an 18 watt with 470k grid reference resistors you use a 0.0022uf cap Most of my 18 watt builds have a Cut control ... as you turn the control up you cut the really high frequencies. The Matchless Br...

Tube socket diagrams are looking at the bottom of the socket ... at the solder connections.

Measure voltages with the tubes installed, DC voltages are made to ground ... measure the heater voltage across the heaters instead of to ground most amps have AC heaters, some have DC heaters