Good point, the new version, v1.1AB, is in post #157. 14th March 2010, 03:48 PM
http://www.diyaudio.com/forums/tubes-valves/161112-what-tubes-tube-amp-16.html#post2118976
Dejalo trabajar al pibe que si sigue typeando empeorará el síndrome del tunel carpiano.
Sorry Guys for my spanish commentary but is a colleague from my same country.
OK- I didn't see this before, but it is definitely an error! If you are using this power transformer, you will want both secondaries in series to give 100V input to the rectifiers. Unless you have some way of boosting the AC line voltage at that point, you simply will not have enough B+ to make it worth running the amplifier in AB mode. So IMO that switch has no business there.
Atmasphere (Ralph?) - since you are so kind to the audio community in sharing some of the fun with us in building OTL circuits perhaps you could have on sale some of the parts as well so that we could buy them directly from you? Truthfully I wont care even if there is a 50% markup, since my effort in sourcing them is more than that. That could be an extension of your parts section on your website.
I should note that the most difficult part for me after years of trials and errors is the chassis, but even so, if I can get hold of a transformer/ capacitor or two that would indeed make my life much much easier.
I terms of potential and design I, for sure, can testify that the sound you get out of any variation of an OTL is superb, after years of blind tests with SET and other circuits, and the difference is by no means subtle. I am currently using a futterman -Rozenblit design with 6c33c which is delightful to listen.
Thanks once again for your efforts and kind input into this venture.
I should note that the most difficult part for me after years of trials and errors is the chassis, but even so, if I can get hold of a transformer/ capacitor or two that would indeed make my life much much easier.
I terms of potential and design I, for sure, can testify that the sound you get out of any variation of an OTL is superb, after years of blind tests with SET and other circuits, and the difference is by no means subtle. I am currently using a futterman -Rozenblit design with 6c33c which is delightful to listen.
Thanks once again for your efforts and kind input into this venture.
Mr. Karsten: Thank you for taking the time to look at that, I didn't see your reply until now. So, just to be clear, the original Atma-Sphere version of the power supply, as posted in message #109 on 3rd March 2010, 02:44 PM, appears to show SW3a toggling the primary of the power transformer between having two primary coils in series for each phase for Class A operation to then taking one coil per phase out of service for Class AB; which in turn switches the hi voltage secondary between 100 vac for Class A and 200 vac for Class AB. Do I have that right? (I'm sorry to beat this issue if it's obvious to the more experienced on the list.)
I built a solid state circlotron that sounds great, so I'm really psyched to step up to this vt version.
Related note, if we want to buy a kit can we buy it direct or only through authorized dealers?
The switch is simply switching a tap in and out, not an entire winding. It could also be accomplished with a small bucking transformer.
We would need at least 10 people and the chassis work would be about $450.00 each. That chassis is designed for toroidal transformers, FWIW.
Lets go people I am 1 of 10 where are the other 9? Also Ralph what about a transformer package?
Since we're talking kits and all, in Sweden we have 230V@50HZ and I'm sure there are others as well. It would be great if the kits were offered with the possibility to choose transformers with regards to the local demands.
I'm interested as well but the price tag will determine if I'm able to.
I'm interested as well but the price tag will determine if I'm able to.
Another idea which may prove to be of commercial interest to Atma - not knowing the hit count on your website- is to post the idea on your website of the possibility of re-issuing the KIT and to allow the visitor to express his feedback as to his intentions to buy one.
Atma would get a feel of the market fairly quickly and everyone would be happy if this goes through, and primarily for Atma knowing if this is worth investing for.
Alternatively we can beg our fellow diyers for a group buy.
Atma would get a feel of the market fairly quickly and everyone would be happy if this goes through, and primarily for Atma knowing if this is worth investing for.
Alternatively we can beg our fellow diyers for a group buy.
I suspect a lot of people would not be interested in the cost of the kit. Many have ideas about what parts they want to use- tube sockets, caps, that sort of thing. So right now the group buy on the chassis seems a good place to start. We can probably figure out something on the transformers too.
I see the kit as transformers and chassis only. Past that we all buy the infill items we like most of all. Is that $4500?
Thx Ralph