MikeC Sixty-One SRT

Amp tinkerers and people who aren't afraid of 700 volts or so in here....

Moderators: Slowy, Capt. Black

User avatar
jeremyb
Chorus of Organs
Posts: 43775
meble-kuchenne.warszawa.pl
Joined: Sat Dec 06, 2008 9:03 am
Has liked: 8858 times
Been liked: 4588 times

Re: MikeC Sixty-One SRT

Post by jeremyb »

Wowsers, sounds glorious!!
Standing on top of the world

User avatar
Jay
Vintage Post Junkie
Vintage Post Junkie
Posts: 8224
Joined: Sat Sep 25, 2010 9:35 pm
Has liked: 1795 times
Been liked: 1470 times

Re: MikeC Sixty-One SRT

Post by Jay »

I am re-reading this thread and noticed I too have downloaded a copy of this circuit of which you posted a small section on page 2:
There are a number of errors on the complete circuit which you obviously fixed. One being that the valve rectifier winding doesn't show the center tap to ground. Don't know how that can be missed.

Anyway, how much does your current circuit still reflect the original?

SRT OS-71.jpg
SRT OS-71.jpg (39.05 KiB) Viewed 3836 times

User avatar
MikeC
Vintage Post Junkie
Vintage Post Junkie
Posts: 3475
Joined: Fri Sep 12, 2003 5:43 pm
Location: Red Beach, Auckland
Has liked: 1529 times
Been liked: 1081 times

Re: MikeC Sixty-One SRT

Post by MikeC »

Very close but reverb different and some errors fixed. VRM & sizzle filter added too. Preamp tubes as per Doug & Pat's. Oh, I have a choke in the power supply for the entire amp's power.
Whakanuia o mea kei a koe

User avatar
MikeC
Vintage Post Junkie
Vintage Post Junkie
Posts: 3475
Joined: Fri Sep 12, 2003 5:43 pm
Location: Red Beach, Auckland
Has liked: 1529 times
Been liked: 1081 times

Re: MikeC Sixty-One SRT

Post by MikeC »

Things have been a little slow of late but #8 has finally found a new home - close to home too! Must be that OCR reduction kicking in already :mrgreen:. #9 under construction.
Whakanuia o mea kei a koe

User avatar
MikeC
Vintage Post Junkie
Vintage Post Junkie
Posts: 3475
Joined: Fri Sep 12, 2003 5:43 pm
Location: Red Beach, Auckland
Has liked: 1529 times
Been liked: 1081 times

Re: MikeC Sixty-One SRT

Post by MikeC »

Sixty-One SRT #9 is all but finished, final cook test to go (it's cooking right now). I need to sell it ASAP (provisional tax) so sharp pricing on this one. Added bonus of 2 x NOS Radiotron 12AU7s instead of usual JJs. 12 months warranty, PM if interested.
Attachments
Topside.jpg
Topside.jpg (1.68 MiB) Viewed 2667 times
Gutshgot.jpg
Gutshgot.jpg (2.06 MiB) Viewed 2667 times
Whakanuia o mea kei a koe

User avatar
MikeC
Vintage Post Junkie
Vintage Post Junkie
Posts: 3475
Joined: Fri Sep 12, 2003 5:43 pm
Location: Red Beach, Auckland
Has liked: 1529 times
Been liked: 1081 times

Re: MikeC Sixty-One SRT

Post by MikeC »

Bump for SRT #9 - $1795.00 to NZG members.
Whakanuia o mea kei a koe

User avatar
olegmcnoleg
Vintage Post Junkie
Vintage Post Junkie
Posts: 5808
Joined: Sat Dec 21, 2013 11:26 am
Location: Awkland
Has liked: 911 times
Been liked: 799 times

Re: MikeC Sixty-One SRT

Post by olegmcnoleg »

MikeC wrote: Tue Sep 03, 2024 12:29 pm Bump for SRT #9 - $1795.00 to NZG members.
That's a phenomenal deal Mike. And a great amp too.

User avatar
MikeC
Vintage Post Junkie
Vintage Post Junkie
Posts: 3475
Joined: Fri Sep 12, 2003 5:43 pm
Location: Red Beach, Auckland
Has liked: 1529 times
Been liked: 1081 times

Re: MikeC Sixty-One SRT

Post by MikeC »

A quick thanks to Bill Warriner for suggested mods to the Sixty-One SRT. From now on all new builds will be v6 (previously v5.2).
V6 essentially has less gain (there's still plenty), a tamed reverb, tamed tremolo and a huge reduction of the inherent idle hum that was caused by the V2 (mixer) cathode coupling - this latter one really bugged me!
Attachments
SRT v6 Finished Topside Pic.jpg
SRT v6 Finished Topside Pic.jpg (2.15 MiB) Viewed 781 times
Whakanuia o mea kei a koe

User avatar
GrantB
ADMIN
Posts: 16626
Joined: Fri Oct 31, 2003 9:04 am
Location: Where I need to be
Has liked: 1524 times
Been liked: 2327 times

Re: MikeC Sixty-One SRT

Post by GrantB »

MikeC wrote: Wed Oct 09, 2024 8:40 am A quick thanks to Bill Warriner for suggested mods to the Sixty-One SRT. From now on all new builds will be v6 (previously v5.2).
V6 essentially has less gain (there's still plenty), a tamed reverb, tamed tremolo and a huge reduction of the inherent idle hum that was caused by the V2 (mixer) cathode coupling - this latter one really bugged me!
These are worthy changes Mike. At the owners expense, would you be able to make these adjustments on previous versions?
"Man is the most insane species. He worships an invisible god and destroys a visible nature. Unaware that this nature he's destroying is this god he's worshipping." - Hubert Reeves

User avatar
MikeC
Vintage Post Junkie
Vintage Post Junkie
Posts: 3475
Joined: Fri Sep 12, 2003 5:43 pm
Location: Red Beach, Auckland
Has liked: 1529 times
Been liked: 1081 times

Re: MikeC Sixty-One SRT

Post by MikeC »

GrantB wrote: Wed Oct 09, 2024 12:31 pm
MikeC wrote: Wed Oct 09, 2024 8:40 am A quick thanks to Bill Warriner for suggested mods to the Sixty-One SRT. From now on all new builds will be v6 (previously v5.2).
V6 essentially has less gain (there's still plenty), a tamed reverb, tamed tremolo and a huge reduction of the inherent idle hum that was caused by the V2 (mixer) cathode coupling - this latter one really bugged me!
These are worthy changes Mike. At the owners expense, would you be able to make these adjustments on previous versions?
Absolutely!
Whakanuia o mea kei a koe

Post Reply