The Amp Garage

I have a hum when I engage the Reverb not the end of the world but something I would like to try and reduce. I am thinking of swapping the cabling from the v4 coupling capacitor and the reverb attenuation point to the reverb potentiometer for shielded cables, would this help? Robrob suggests a .002 ...

426 volts The output transformer must have been wired wrongly during manufacture as when the wires were swapped it started working properly Thank you for your advice along the way I may or may not modify it later depending on how I get along with it, but for now I am very happy with the noise it makes

All finished still need to check final bias Sounds really nice
Thank you guys for your help
Trying to work out what to build next maybe a Princeton reverb but like the idea of a Dumble or Vox based amp what recommendations do you guys have for Dumble style builds who makes good boards to base it on?

Thanks Steve that seems to have fixed it, the Voltage has come down to 426volts. I don't fully understand what happened, so for now Ill just go with it, and do a lot more reading up on it. I have to chase the filthy lucre for the next couple of days, so this will have to wait till then to do more me...

Thank you Steve It is the middle of the night here so Ill give that a go in the morning

Went through the measurements again today and got different results the biggest difference is I used a 8ohm 100watt resistor instead of the speaker One of the reasons that I stopped yesterday (aside from the power tubes glowing bright red and giving off heat like an electric radiator), was the high ...

I will put those resistors in tomorrow thank you Steve

Thank you both At this point I am concerned at the high plate voltage at 470 volts it is about 55 volts higher than it should be and about 45 volts higher than Sluckeys schematic Surely if I bring the plate voltage down the bias voltage will fall into line as well The rectifier is an 5AR4 I have not...

Ok pretty well all done but I have a problem My voltages at the output tube plates is way high at 470 volts. Also if I try raising bias higher than about - 50 volts I start getting redplating in both 6v6's I am using the correct transformers etc Hammond 290BEX power transformer and Hammond 1760H out...

Getting down to the business end now, will spend a bit of time rechecking the build then start up and scope
Any constructive criticism / obvious errors welcome

Ok another dumb question Im using a Hammond 290 BEX power transformer, there is a white and a black 240 volt AC input wires here in Australia the white would be active (positive) and the black neutral (negative ) is this the case with this transformer, being AC does it make any difference? I saw an ...

PXL_20230830_022719589.jpg Slowly getting there in the end I'm doing this pretty well stock standard, hoping to finish in the next week or so Question does the polarity of the choke matter there are 2 black wires I assume one from the outside of the coil and one from the inner is this something to ...

Just about finished the chassis stuff, now for the eyelet board
Any constructive criticism welcome

Thanks guys. I think I will go under I'm using tezfel shielded for the input cables, I'm using a TAD fibre board which doesn't seem to have full in and out holes so I'm just going to scoot the wires underneath everything I'm using a Hammond 270BEX power transformer which doesn't have a centre tap fo...