audio-talk

Yeah, that's why it's going to be something simple and silly . And why I first suspected the source. Hmmm.

The IT did cross my mind. Voltages look okay but I might have to try replacing with a cap. But why would both ITs go down?

Think I've got a signal generator somewhere, but this is getting technical now .

Tapping the 300B gives a little sound through the speaker, but not the 10Y or 26 as far as I can tell. Putting the meter probe on the anode of each valve produces a little crackle through the speaker. Hmmm. The source works cos I've checked it on a different amp, and touching the first valve's anode...

Good idea Steve, I'll try it. I suspect the problem's in the amp somewhere though as I've just connected the sources and switcher in to different amps and they work fine. Before this I fed the grid of the 300B directly from the source and this didn't work either. Back in a bit.

Yep, the heaters are on and voltages correct, HT's right as is voltage on top of each valve. It's going to be something very simple and silly I think!

Don't think so. The amp voltages are fine andthe only change is the OPT secondary ground, unless the earth has gone in both ICs.

At least that was an easy fix Phil! We can live with those

Gosh, I hadn't realised how long it was since I last posted about this. I rebuilt the amp a little while ago on to just two boards - an audio board and a PS board. Actually I cut the PS board in two otherwise it would have been too heavy. Still, it started out as 5 boards and is now down to just 1 a...

You don't love it to bits then?

Thanks chaps. So a 19 bit HSS drill set for £7.54 might be false economy? An equivalent cobalt set is £23.49, which is nearly 4 of the cheap sets. You pays yer money and makes yer choice I guess?

Question for those who know their bits (stoppit!) What's the difference between the different bit types? HSS, HSS Ground, titanium coated, cobalt? Presumably the more expensive the better. But my cheap set from some DIY shed or other which has titanium coating seems to have gone blunt much quicker t...

while i was at it i slipped while i was typing and accidentally ordered a couple of FT17H tweeters and cap/resistors (well i've tried the single driver experiment now haven't i) Don't you just hate it when that happens :). can i use my laptop with a mic and some software to measure the in room resp...

Nick wrote:Bass guitars make a good club at those times.

ROFL one of the funniest things I've seen on here in a long time

Rod Coleman on DIYAudio is in the process of releasing some modules which sound very promising. Check out the Tubes/Valves section. If you're prepared to build yourself (as we are) then pricing looks favourable (Rod hasn't released prices yet on the forum, but it should work out cheaper than the eba...

And the last