Ray P wrote: ↑Wed Apr 08, 2020 11:11 am
Nice addition Steve.
When you describe your Rocky as the best amp you've ever built does that relegate the 13E1 OTL?
Not exactly Ray. The OTL, like others of its ilk has a unique way with music. The power consumption is the thing that bothers me about it. I’m glad I built it though as it was a major test bed for developing the multiple power supply approach I’ve used in the Super Rocky.
As a result of the learning gained from the OTL’s power supplies, the Super Rocky is certainly the best sounding and most musical non-OTL valve amp I’ve built to date.
Compared to my 2006 amplifier, the Super Rocky incorporates a completely different power supply setup: choke input rather than cap, one power supply per stage and a little tweak to the output stage choke to make it seem twice the inductance. Hell, it can’t even use EL34s. So though, superficially similar, it isn’t the same thing at all. Not really. I need a different name for it.
Good for you Steve, it's great that it works for you and you seem good and chipper.
As for a name, Marciano follows on nicely from Rocky and you could include the strap line '...the only heavyweight to have finish a career undefeated'.
Ray P wrote: ↑Wed Apr 08, 2020 11:56 am
...As for a name, Marciano follows on nicely from Rocky and you could include the strap line '...the only heavyweight to have finish a career undefeated'.
Marciano...that scans nicely.
There’s no denying, this amp is a great sounding piece of kit. The modern production Genalex KT77 bias up exactly the same as the GEC/Gold Lion/MO Valve original data sheets show, and really do sound superb; which is a good thing, because the old valves are now virtually unobtainable NOS. I dread to think what the prices of those would be, even if you could get hold of them.
I really must think about doing a valve phono stage. I still have the instructions for the WAD Phono II and there is a circuit diagram for it in the back of the booklet. A multiple 250V power supply approach might be good with this circuit, and maybe a 6H30pi cathode follower output stage, rather than the puny ECC83 of the existing jobbie. I’m rambling now.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
I still really liked your single valved otl. Best otl by a mile that I've heard, and I'm sure it plays every thing now with the modded power supply. That amp goes to show how much the single valve is capable of.
Back on the super rocky front I would guess it will take all sorts of valves. Once this is over I'll get a few oldies sorted for a, session. Will it take the vt75's, el37s and maybe mesh plate el35s should sound good too (I need to test them 1st), if the voltage is low enough...250max.
Hopefully 6 months or so..
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number
steve s wrote: ↑Fri Apr 10, 2020 10:03 am
Looks a nice amp Steve I bet it sounds good..
I still really liked your single valved otl. Best otl by a mile that I've heard, and I'm sure it plays every thing now with the modded power supply. That amp goes to show how much the single valve is capable of.
Back on the super rocky front I would guess it will take all sorts of valves. Once this is over I'll get a few oldies sorted for a, session. Will it take the vt75's, el37s and maybe mesh plate el35s should sound good too (I need to test them 1st), if the voltage is low enough...250max.
Hopefully 6 months or so..
Aye, it’d be good having a session with different valves. I’ll have to mod it slightly to give switchable cathode resistor values on a selector switch. EL35s are out. There’s 330V across the output valves.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
simon wrote: ↑Fri Apr 10, 2020 10:35 am
That sounds dangerously expensive Steve
These are listen only.. the vt75s are too nice sounding to part with, very much a px4 type of sound.
Steve heard them a few years ago in his kt66 pp amp. They where the best on the day along side kt66s and others.
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number
I’m not as qualified to talk phono stages as many here. But Steve you mentioned possibly building the wad phono stage. It was a good budget self build phono stage. True Reality phono stage sounded better to me. I’ve built both. Both were are fair stretch ahead of the stock EAR phono stage and better than it after the Thorsten mods, which to me barely made an impression.
In those days I never quite got around to the one whihc was praised by the better names I leraned could be trusted in those days; AusLerch (sort of play on names Arthur Lurch design adapted by some Ausy, the circuit for which was readily available online in the ‘90s but last time I searched for it the original is no longer available. But there is plenty of info about the method.
Nick G and Mark J have both built versions of the concept afaik.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
Paul Barker wrote: ↑Mon Apr 13, 2020 9:32 am
I’m not as qualified to talk phono stages as many here. But Steve you mentioned possibly building the wad phono stage. It was a good budget self build phono stage. True Reality phono stage sounded better to me. I’ve built both. Both were are fair stretch ahead of the stock EAR phono stage and better than it after the Thorsten mods, which to me barely made an impression.
In those days I never quite got around to the one whihc was praised by the better names I leraned could be trusted in those days; AusLerch (sort of play on names Arthur Lurch design adapted by some Ausy, the circuit for which was readily available online in the ‘90s but last time I searched for it the original is no longer available. But there is plenty of info about the method.
Nick G and Mark J have both built versions of the concept afaik.
There is a thread on here that you might remember Paul.
Paul Barker wrote: ↑Mon Apr 13, 2020 9:32 am
I’m not as qualified to talk phono stages as many here. But Steve you mentioned possibly building the wad phono stage. It was a good budget self build phono stage. True Reality phono stage sounded better to me. I’ve built both. Both were are fair stretch ahead of the stock EAR phono stage and better than it after the Thorsten mods, which to me barely made an impression.
In those days I never quite got around to the one whihc was praised by the better names I leraned could be trusted in those days; AusLerch (sort of play on names Arthur Lurch design adapted by some Ausy, the circuit for which was readily available online in the ‘90s but last time I searched for it the original is no longer available. But there is plenty of info about the method.
Nick G and Mark J have both built versions of the concept afaik.
The Aussie Loesch thing looks interesting. Virtually every diagram I see on the internet has only the one power supply. I’ve already heard the very considerable benefits of using multiple power supplies; one per stereo stage and my NVA Phono1 is a completely different kettle of fish with a big remote power supply, than it was with the single, built in PSU.
I’m torn between building a completely new valve phono stage, or reverse engineering the single regulator board in the NVA stage and converting it to four regs (2 per channel) all fed by the giant +35/-35V remote supply.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
