SV811-3

[Cressy Snr]

I have a similar beast…
…I had smps feeding lehane regs and swapped it for rod's linear design. Smps won't be going back. Huge difference IMHO…
…Good luck!

Thanks Stephen. Reading your experience, I’ll be going linear for the DC to the Coleman regs I think. Failing to listen to those who’ve been doing this thoriated tungsten tube thing for years would be a bit silly.

[izzy wizzy]

There's a lot of nice things in that amp. Choke input supply, beefy capacitance, choke smoothed bias, Coleman regs.

Tower style will make it small in real estate terms. I found sketchup my friend and it's free. Use it for all my layouts now.

[Cressy Snr]

There's a lot of nice things in that amp. Choke input supply, beefy capacitance, choke smoothed bias, Coleman regs.

Tower style will make it small in real estate terms. I found sketchup my friend and it's free. Use it for all my layouts now.

Cheers Stephen, I'll take a look at Sketchup.

[Cressy Snr]

The breadboard is no more. The parts have been stripped out and put in cardboard boxes, ready to be assembled into the vertical stacked job. Making a series of sub-assemblies then testing each one before moving to the next stage is probably the best way of going about things. The sub-assemblies (modules) can then be built up into the finished product.

[simon]

Just to say that a common primary for the filament transformer isn't regarded as ideal, I think its fair to say that Rod would recommend separate trafos for each channel. But it's what ya got and iron isn't cheap. Just thought I'd mention it.

[Cressy Snr]

Just to say that a common primary for the filament transformer isn't regarded as ideal, I think its fair to say that Rod would recommend separate trafos for each channel. But it's what ya got and iron isn't cheap. Just thought I'd mention it.

Aye, read that in his PDF from his site, but at least I have two 9V secondaries from which to hang one raw DC supply per reg. Also the trafo is a toroidal and he doesn’t recommend those either. I do however have a 200VA isolating transformer that could be used to ameliorate the ‘toroidal’ problem.

[simon]

Just checked, the filaments are only 6.3V but 4A! That's probably a 75VA trafo. Don't think I've got anything suitable in 9V you could try to see if you can hear any difference. Will have a look though just in case.

[Nick]

Just to say that a common primary for the filament transformer isn't regarded as ideal, I think its fair to say that Rod would recommend separate trafos for each channel. But it's what ya got and iron isn't cheap. Just thought I'd mention it.

Does he say why he recommends that? Interested what the reason is.

[Nick]

Also, I would consider how long that gas regulator is going to last charging those 200uf of capacitance on startup.

[Cressy Snr]

Also, I would consider how long that gas regulator is going to last charging those 200uf of capacitance on startup.

Not the brightest of ideas was it.
I think it’ll be a completely separate power supply for the Aikido section. Be daft not to, given the opportunities provided by the stacked chassis arrangement. I’ve been having a look at Stephen’s site as well as the Thomas Mayer products and between the Mayer 300B and Stephen’s GM70, they show how to do it properly.

[Cressy Snr]

Just checked, the filaments are only 6.3V but 4A! That's probably a 75VA trafo. Don't think I've got anything suitable in 9V you could try to see if you can hear any difference. Will have a look though just in case.

Cheers Simon.

[izzy wizzy]

Making a series of sub-assemblies then testing each one before moving to the next stage is probably the best way of going about things. The sub-assemblies (modules) can then be built up into the finished product.

Yup. Worked for me.

[izzy wizzy]

Cheers Stephen, I'll take a look at Sketchup.

If you do, I'll send you a sample layout of mine so you can pick it apart.

It's best to make a whole bunch of blocks representing the parts and then move them round how you like and then group them further into modules.

Don't whatever you do make it one thing all at once. It'll drive you nuts!

[Nick]

I think it’ll be a completely separate power supply for the Aikido section.

Just remember that the whole point of the Aikido is good PSRR, so i you are going to use excessive force in its power supply, you may as well just use a cathode follower.

[Cressy Snr]

I think it’ll be a completely separate power supply for the Aikido section.

Just remember that the whole point of the Aikido is good PSRR, so i you are going to use excessive force in its power supply, you may as well just use a cathode follower.

Point taken Nick, I'll just replace the gas tube with a suitable resistor to drop the 150V and leave things alone.