Rexton's Valve System - Upgrade Blog

[Wakefield Turntables]

Sure, but the point is that I no longer have valve regulation in my Croft - it's been replaced by MOSFET solid-state, which in that particular application is just all-round better.

And yes, my PSU has been externalised and considerably beefed up. There are about four of those transformers, what's in your amp (and bigger) inside it, individually powering different parts of the circuit. Josie (Black Adder) has gone even further with hers. You should ask her to post some pics - it's quite something!

So did you hear any difference with the M8098?

Marco.

OK, I'll see what I'm missing. Probably have a word with Josie and see what the deal is. Could be something to look into for the new year. I'm not sending the Croft off before Xmas, I have many Jazz and Whisky session planned over Xmas.

Marco.

Blimey, your Eager with the 8098. Yes I have seen a nice up-tick in detail retrieval, not massive but well worth the outlay. It's difficult to say just how the valve has had an impact on the system it just sounds, "right" which I know sounds a little strange but that's the only way of really detailing what I'm hearing. I've always had a very wide soundstage with massive amounts of separation between instruments, plenty of depth, very 3D. The wardrobes just disappear. I'm getting a little more of everything that I've just described. What about you, what are your thoughts?

[Marco]

Yeah, that makes sense. Enjoy yourself over the festive period and have the mods done in stages. Glenn's always up for doing that type of work, so I'd give him a shout and he could also advise you of any other tweaks he'd recommend

I reviewed the M8098 on my gallery thread.

Marco.

[Wakefield Turntables]

Hey Marco, just had a word with Firebottle. I do indeed have MOSFET power regulation installed. So now probably think about externalising the Traffo's. Tried calling Glenn todat but no reply.

[Marco]

Mmm... I'm no expert, but I don't see how:



There are no Mosfets there I can see, and that looks suspiciously like a regulator valve to the left of the mains transformer, attached to the Jensen PSU caps... Which btw, being electrolytic types can also be upgraded for quality polyprops, such as the Mundorf Tubecaps I use: https://www.hificollective.co.uk/com...p_tubecap.html

But that can be done when the PSU is externalised and increased in capacity. However, perhaps you could ask Alan to comment here and explain how the Mosfet regulation has been installed?

Marco.

[Wakefield Turntables]

From Alan,

"The line stage valves effectively have both Mosfet and valve regulation.

The main supply is valve regulated that feeds all stages, line and phono.
The line stages were converted to mu follower circuit which incorporates Mosfet regulation as well.

Mosfet's used = IRF820"

Sounds impressive, I'm sure people "in-the-know" will clarify what all that means.

[Marco]

Interesting... Yeah, I'm not sure, but this is what the Mosfets (which would be inside the heatsinks shown) look like in my Croft:



So I was looking for something like that in yours... All I can presume is that he's managed to construct a bypass of some kind, thus allowing the original components to remain in place.

Marco.

[Firebottle]

Marco there is more than one way to skin a cat, as they say.

Look at the main aluminium plate, just above each Silver Z cap there are the Mosfets, bolted to the plate as a heatsink.

[Marco]

Yesh, I spy it now!

So, is what looks like a rectifier valve, to the left of the mains transformer, now redundant? It also appears to be connected to the Jensen PSU caps... Or if it's not a rectifier valve, what is it? Is it an ECC83 (with an 85A2 underneath)? Being somewhat obscured, it's difficult to see.

Marco.

[Ali Tait]

Interesting... Yeah, I'm not sure, but this is what the Mosfets (which would be inside the heatsinks shown) look like in my Croft:



So I was looking for something like that in yours... All I can presume is that he's managed to construct a bypass of some kind, thus allowing the original components to remain in place.

Marco.

Those are heatsinks for the MOSFETS mate.

[Marco]

Lol - yeah I know... That's why I said mine look like that *with Mosfets inside*

What threw me initially, was that I was looking for some big black heatsinks inside Andy's amp, which I knew would contain the Mosfets, but of course couldn't see any for reasons since given!

Marco.