[L0rdGwyn]

I see Sowter transformers in the 2nd picture.

That's right! All custom work done for this amplifier, it was quite a wait. The output transformers are 5K:8ohm, gapped for 60mA DC, but the truly impressive feat is the big mains transformer. It has a 300V B+ winding, 100V B- winding, two 10V 4A filament windings for the 801A, a 6.3V winding for the pentode and cathode follower heaters, and three electrostatic shields. It is a monster, and working out very well.

Just finished actually, having a listen now

Hey look what you did @Xcalibur255 ! I finally did it, now it just needs a box.

 

[UntilThen]

That's right! All custom work done for this amplifier, it was quite a wait. The output transformers are 5K:8ohm, gapped for 60mA DC, but the truly impressive feat is the big mains transformer. It has a 300V B+ winding, 100V B- winding, two 10V 4A filament windings for the 801A, a 6.3V winding for the pentode and cathode follower heaters, and three electrostatic shields. It is a monster, and working out very well.

Very impressive indeed and I'm envious. A little setback for me when I learn that Sowter will stop making customized power transformers. Not to be deterred, will still go ahead with Sowter output transformers and another reputable power transformer for Odyssey.

That 801A build is fascinating. Along with Odyssey being built in June, I have a 300b amp built ongoing. What say you, build me a 845 in 2023? That is if I'm still in this world of tube amps.

Stay well.

 

[L0rdGwyn]

Very impressive indeed and I'm envious. A little setback for me when I learn that Sowter will stop making customized power transformers. Not to be deterred, will still go ahead with Sowter output transformers and another reputable power transformer for Odyssey.

That 801A build is fascinating. Along with Odyssey being built in June, I have a 300b amp built ongoing. What say you, build me a 845 in 2023? That is if I'm still in this world of tube amps.

Stay well.

I wasn't aware they had stopped, must be part of the Carnhill takeover, that is terrible news really, but very glad I had this one made beforehand. There are very few companies still doing it at this point, I hope this isn't a trend. I'm sure you will be happy with another mains transformer, it is really only an issue when you need oddball winding combinations.

Sounds like you have some very nice amplifiers on the way, I'm sure you will be pleased, I didn't know about the 300B. 845 is a beast, have to be okay with high voltages in your amplifiers, keep the doggies and kiddos away

 

[L0rdGwyn]

Things may change as I will likely play with increasing / decreasing the amount of negative feedback, but here are measurements of this particular iteration.

Output Z: 1.53ohm
Power: 6.2W into 8ohm

1W into 8ohm FFT



Frequency response

 

[UntilThen]

Sounds like you have some very nice amplifiers on the way, I'm sure you will be pleased, I didn't know about the 300B. 845 is a beast, have to be okay with high voltages in your amplifiers, keep the doggies and kiddos away

Known only to me but the 300b project would have gone to you but I thought you needed alone time... which we all do.

The 845 would be a speakers only amp to drive my tower speakers. Kiddos have grown and they are getting me a LCD4... should be arriving next week. As for doggies there's only a cute cavoodle and he's trained to tube roll for me.

 

[leftside]

Very impressive indeed and I'm envious. A little setback for me when I learn that Sowter will stop making customized power transformers. Not to be deterred, will still go ahead with Sowter output transformers and another reputable power transformer for Odyssey.

That 801A build is fascinating. Along with Odyssey being built in June, I have a 300b amp built ongoing. What say you, build me a 845 in 2023? That is if I'm still in this world of tube amps.

Stay well.

I'm still waiting for the Sowter output transformers for Red Dwarf. Using Lundahl for the power transformers.

 

[UntilThen]

Interesting Leftside. Any special windings on the Lundahl?

 

[leftside]

Interesting Leftside. Any special windings on the Lundahl?

Don't think so. @A2029 would know for sure.

 

[L0rdGwyn]

I lugged the beast into my stereo. The sound is superb, very impressive. Will do a little more tinkering, but will begin designing the box. The aesthetic choices are already made, just a matter of finalizing the layout and getting it in AutoCAD.

 

[Xcalibur255]

If I really did have some influence in this then I gladly accept responsibility for what has come of it.

Love the Zenith radio btw. Now you just need to find and restore a Super Air Castle one (yes, I am obsessed with this brand name..... makes me smile every time).

Good to hear from you Keenan.

 

[Galapac]

@L0rdGwyn thanks for dropping by for an update and glad to hear you‘re happy. Keep us updated on your projects and I would love to see the beast when it has its clothes on.

 

[L0rdGwyn]

If I really did have some influence in this then I gladly accept responsibility for what has come of it.

Love the Zenith radio btw. Now you just need to find and restore a Super Air Castle one (yes, I am obsessed with this brand name..... makes me smile every time).

Good to hear from you Keenan.

Thanks! I think it has a nice aesthetic, have to put it somewhere it will be seen hope everything is going well with you @Xcalibur255

@L0rdGwyn thanks for dropping by for an update and glad to hear you‘re happy. Keep us updated on your projects and I would love to see the beast when it has its clothes on.

Will do @Galapac ! I would say at least a month, probably longer before it gets its chassis. Going to take my time with it and get it right.

After that is an amplifier on a whole new level of crazy, we'll see what happens with the HK54...another long-term type of design, but now I can play with it on my protoboard.

 

[whirlwind]

Hey Joe - yes, very! I am also in the middle of a staycation, so DIY efforts have been off the rails, I have gotten a lot done. Really happy with how the radio is turning out, sort of a bigger PITA than I anticipated, HA! Recapping the entire thing was a LOT of fun. It is a belated birthday gift for my girlfriend.

The situation at work is much better! Hopefully it keeps trending that way, I think it will. Hope you and yours are well and keeping from going stir crazy. We'll see what those Brownies do in the draft in a few days, right in my backyard.

Thanks for posting pics , Keenan. Some killer stuff.

At some point I am hoping to see an EL34 amp project

I am pretty excited about the draft. I am hoping the Clowney thing works out and maybe they can sign Richardson back.
I have no clue who they may draft...would be awesome if he was a starter though.

Great to hear from you....stay healthy and have fun.

Killer looking tubes, trannies and cans!

 

[CJG888]

Maybe I can persuade you to go down the idler wheel turntable rabbit hole next...

 

[Zachik]

By the time this amp is done - @L0rdGwyn is going to have impressive thick arms from lifting and moving all that iron around!!

Some dude: "How did you get those arms? Which gym do you go to? Who is your trainer?"
Keenan: "Gym? Trainer? I was just building a tube amp!"