audio-talk

Mike H wrote:Nuffink on the web takes your fancy? Or you want a real paper one?

Can you recommend any good ones for a (scope) numpty? Sort of an ABC for those of us, well me anyway, that doesn't really know how to use a scope?

al newall wrote:Try this method.


http://t3.gstatic.com/images?q=tbn:ANd9 ... hgkMmO_58=

I wasn't expecting that!

Right, I'll give them a go then chaps. Thanks for the feedback.

I thought I'd got the filter for my supertwatter just right. I'd spent a long time with various values of capacitor finally settling on 2u2. The L Pad attenuation I worked out from an online calculator and the values seemed to work fine. So I finally soldered it all together instead of having messy ...

Ah the eternal 300B debate ~ should it be 2.5k, 3k, 3.5k, 5k, 6.8k ...... This 'ere Madness amp has had 5k amorphous, 2.5k c core and now Bud's 4.545k OPTs. I think quality of the OPT is probably more important. That said Bud is a really interesting guy to correspond with as he talks about minutiae...

Honestly we have nothing better to do :D And for that you earn the highest order of recognition "No idea why I do this anymore" 8). In comparison I am simply not worthy. A mere fiddler. These Onetices have 4 hours on them now and I have to say they're very interesting. Detail retrieval is...

"plugged the IC back in to the switcher", what's that about then? http://livinginthepast-audioweb.co.uk/kbf/th_scratchhead.gif Er, it's a passive pre I use with the WE91s which I'm also using with Madness so I can easily switch between sources. It was superfluous to the story as I proved ...

Yeah, work really gets in the way of my social life. Actually, work for most of the time is life. Oh well. So, update time. I was hoping to have a bit of time this evening to play but work (grrr) saw an end to that. I did find 10 minutes before cooking tea to dig the old sig gen out and follow Capta...

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...