audio-talk

Something else as well now I've had a sleep. The way I have the cap connected will bypass the cathode resistors to ground, which will substantially increase the gain of the first stage. The first stage is a 12AX7 high gain valve which makes the relative increase the worst case scenario as there aren...

Hi Nick Couldn't leave it alone as it was nagging at me. So I had a nice cup of tea, said my relaxation mantra and armed with the circuit diagram and a very strong pair of reading glasses I found this http://homepage.mac.com/scress1958/.Pictures/oops.gif What is this going to do to the feedback? I a...

Thanks Nick I might just do that. I know you managed to sort Simon's Blatting 2A3. after he got completely stumped as I seem to be. I don't yet know why and I'm leaving it for tonight but there seems to be -6v of feedback coming along the left channel but only 1.5V coming back down the right. Could ...

Paul
you have two PMs

Oh dear, Here we bloody go again! I'm giving up with this neatness lark. It's clip leads and rat's nests from hereon in. So what seems to be the trouble then? Right. The HT to the output stage is isolated by fuses which are removed whilst the checkout is in progress. So far so good. Everything check...

Hi. There have been anumber of developments with the Metronome speaker Martin King has come up with a proper baffle step correction circuit for the Metronome FE108EZ version. He visited Jim Shearer in New York, who had just completed a pair of the FE108EZ speakers http://www.diyaudio.com/forums/show...

That's it! Apart from wiring in the input cables to the selector switch the OTL is completed. It has been powered up and tested without the valves, just to check that the right voltages are appearing in the right places, and with the right polarities. One fault was found with the left channel bias v...

The job is nearing completion now. Here are a few pics of the progress made over the past couple of days. http://homepage.mac.com/scress1958/.Pictures/OTLtxs.jpg On go the four transformers. The Sowter at the rear has two HT windings for the driver and output stages. Next size down is the heater tra...

Here is the progress so far today. All the hardware has been mounted on the chassis apart from the heater, bias and preamp transformers. These need their looms prewiring and all their the tags double insulating before they are fastened in their final positions and the cover is fitted. A few pics bel...

OK The chassis is about done. Here is what it will look like with the valves in. I added some nice little tapered legs, made from some oak I found in the cellar. The result is pure Festival of Britain :D http://homepage.mac.com/scress1958/.Pictures/OTLdone.jpg Here is a close up of a veritable fores...

Now that's what I call nice.

Steve

Nick wrote:
how about a couple of jacobs ladders at the back to add that extra touch .

I don't think the missus would appreciate blackened curtains and the ozone would get a bit strong

Steve

Hi Colin
Welcome to the mellow forum.

Steve

Before I can get the PSU sorted, the chassis needs doing. This is what I have been concentrating on over the past week. The look of the casework has been heavily influenced by 1950s radiogram consoles. http://homepage.mac.com/scress1958/.Pictures/OTLchassis.jpg The two ivory knobs are from my Mother...

Wow! does it work!? It's been checked out on a static test with a multimeter and everything seems to be wired to the right places. I haven't built the power supply yet but as soon as it is done and commissioned then the driver stage will be tested with the HT applied and commissioned before the pow...