I've received the transformers about 3 weeks ago after a long, long wait. However, timing is bad right now with lots going on this summer with my job and family. It will likely be September until I can get back to this project.
I think you will like this circuit with the plate to plate feedback, I've built several and really liked all of them. BTW, those output transformers you ordered are the same size as Dynaco Mark III opt's so it should sound really good!
I was thinking about replicating one of the old British Quad amplifiers but I have been out of the electronics business and things have changed a lot since 1969 when I was a young man. The first problem is I have heard about capacitor failure a lot and where do you get good quality components in the UK ? And then who still makes good valves. The old UK companies like GEC have been brought out and no longer exist. But thanks for the great videos. My mind is still curios despite being an old man myself.
Not sure if this is common knowledge or not, but I'll just put it out there for you; The Kiwame resistors seems to be exact same as KOA SPR2 and SPR5 carbon film resistors under a different name, and these are available at much lower price from places like Mouser and such. I have some KOA as well as some Kiwame, and they are EXACTLY alike, so my guess is the Kiwame brand is just made by KOA and sold as boutique parts. Unfortunately I had already purchased my Kiwame resistors when I discovered this, but for next project I will go for the KOA resistors instead :-)
Your right about this being a expensive hobby, I have a few amps under my belt that beat up my wallet. Have you ever ordered transformers from Pacific? They say no job to small for them, I know they are the Holy Grail for the Train Wrecks and I would love to know if anyone has used in a stereo amp. It seems the used market for console amps have take off in price and I don't see the benefit of buying that way anymore, unless I know I'm getting a great deal by chance. I have used Edcor's but wasn't happy with the Blue Color. The 807 is already in the to order list, Id like to do a 2A3 but those are pricey
ASK MARK: I watch videos on guitar amps and they have output tubes connected in parallel. Could you explain how doing tubes in parallel increases the output power with regards to current and plate voltage
The Solens would be bottlenecks IMO. I liked the old Panasonic polyprop orange drop types better with copper leads if on a budget. But I think they were discontinued.. Koa Speer makes/OEM’s Kiwame. I think they are available at Mouser, but in very limited values..
I've received the transformers about 3 weeks ago after a long, long wait. However, timing is bad right now with lots going on this summer with my job and family. It will likely be September until I can get back to this project.
Have you considered (Amps Parts Direct) uncle dog says they make the best Transformers? Isn't it better to build the Transformers on a separate chassis and have them behind your speakers? Having shorter speaker cable is better isn't it! having the multiple wires gk back to the amplifier. if you can get military vehicles like tanks plug and sockets? that are multi pin 6, 8, or10 what is what you want to use they are gold coated with high quality water proof seals and are lockable. British army surplus
Amp parts Direct doesn't make any transformers, they are a reseller like lots of others. The classic tone uncle doug mentioned is what I used in the SE807 build for the power transformer, I've used them a lot.
Don't know about that John. For a PP amp using UL, there would be five conductors at around 300volts connected between amp and speaker, running around furniture and over carpet.
$1.10 a resistor! Try mouser.com. you will hate the website it's terrible but search 261-100k-RC replacing the 100k with the value you need and order them with a minimum of 10 quantity per value and it goes from $0.23usd per to $0.075 per for a whopping total of $0.75 for 10. They are 2w. In a pinch with back order go with 281-100k-RC. They are a smaller body. Theoretically less volume to dissipate heat but still rated for the same 2w.
They showed up about 2 weeks ago. But sadly, they hit at a bad time. Moving kids home from college, work travel, etc. Likely a few more weeks until I can start the series back up.
