Lost interest, and too much else that takes priority. No need for phono and I would be building a more classic circuit with more common tubes when the time comes.
90% of my projects are power amps and some PCB stuff these days for the Salas 6v6, and some other simple designs.
Was looking into a power amp for the next build to pair with this, was looking at the dynaco st70 or the baby huey. You have any recommendations? Something easy enough for an noob dive into?
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All my projects are like this, just put it into storage, in a year or so, or a decade, the interest will come back and you can put yet more money into and once again stop before completion and put it back into hibernation. I am still working on my 2A3 project since 2012, it was active for awhile last year whilst I drilled and painted the chassis and now it's back hibernating. 😎
I mean, sometimes. 🙂
I recently used a project box I bought back in 2010 finally to house something. This summer I finished a set of cigar boxes into simple test speakers. I fixed a few older builds that had damage from failed (cheap) parts. I built a Fender Princeton 5F2-A out of spare/extra parts this winter. Slowly but surely "clearing out the backlog" so to speak. All this in parallel with new projects that get worked on as time allows.
I'm revamping/setting up my 12x15" workshop space (think mother in law unit sort of, with frmed walls ready for insulation and drywall) and slowly clearing out things I know I wont use. This project PCB is one of them. I may have to make a post for some parts/tubes/gear that i need to re-home soon.
I recently used a project box I bought back in 2010 finally to house something. This summer I finished a set of cigar boxes into simple test speakers. I fixed a few older builds that had damage from failed (cheap) parts. I built a Fender Princeton 5F2-A out of spare/extra parts this winter. Slowly but surely "clearing out the backlog" so to speak. All this in parallel with new projects that get worked on as time allows.
I'm revamping/setting up my 12x15" workshop space (think mother in law unit sort of, with frmed walls ready for insulation and drywall) and slowly clearing out things I know I wont use. This project PCB is one of them. I may have to make a post for some parts/tubes/gear that i need to re-home soon.
I just got into this, so maybe I could save a few buck picking up some of your old toy. I would imagine shipping from SF to Rancho Cucamonga wouldn't be too expensive.
Give me a few days and I'll take some photos. I've never actually used the balance pot so I think I could just have left it out.
Hey me again, looking for some recommendations for the power transformer. Couldn't really find one that fit the specifications of the board. Any thoughts on these? Or suggestions? If there are other models from Edcor or Hammond I should check out? Thanks in advance.
https://www.ebay.com/itm/372626930885
https://www.ebay.com/itm/254320907028
https://www.ebay.com/itm/372626930885
https://www.ebay.com/itm/254320907028
I'm using a transformer similar to this:
https://www.aliexpress.com/item/4001106129195.html
But you'll probably need one for 115V.
https://www.aliexpress.com/item/4001106129195.html
But you'll probably need one for 115V.
Seeking advice from the pro and vet builders on PT. Technically, could I make this work? Since it provides 2 x 6.3, I could combine for a 12.6 voltage, for the heaters? This was slightly cheaper and quicker shipping. Apologize for the bombardment of questions. Thanks in advance.
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This issue to be careful of is the heater on the recitifer may not be happy sharing the heater supply with the other tubes where the heater supplies should be elevated to around +70V to +80V to suit the circuit. Most rectifiers have heaters that need to be elevated to B+ and those that have data sheets saying they can be run without elevation may not tell you how long the tubes will last when you don't, due to the voltage stress across the heater insulation and heat-cooling cycles over long-term use.
So if you plan to combine the two 6.3Vac windings for 12.6Vac you'll need to be careful about the rectifier specifications. Also, a rectifier failure can result in a short to the heater so that now all your heaters, if on a common supply, are sitting at high AC voltage from the B+ transformer winding which will not be at all good for the rest of the tubes. If you can keep a dedicated winding just for the rectifier, that is usually preferred.
Anyhow, the 6X4 and it's brothers (e.g. EZ90) are specified to be suitable to not elevating the heater voltage, it's an indirectly heated rectifier with insulation designed to withstand more than the B+ voltage in this Kondo clone. If it's a good quality specimen, perhaps protected by series SS diodes, the rectifier may be just fine - I have no experience to draw from on that.
So if you plan to combine the two 6.3Vac windings for 12.6Vac you'll need to be careful about the rectifier specifications. Also, a rectifier failure can result in a short to the heater so that now all your heaters, if on a common supply, are sitting at high AC voltage from the B+ transformer winding which will not be at all good for the rest of the tubes. If you can keep a dedicated winding just for the rectifier, that is usually preferred.
Anyhow, the 6X4 and it's brothers (e.g. EZ90) are specified to be suitable to not elevating the heater voltage, it's an indirectly heated rectifier with insulation designed to withstand more than the B+ voltage in this Kondo clone. If it's a good quality specimen, perhaps protected by series SS diodes, the rectifier may be just fine - I have no experience to draw from on that.
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Personally I think it'll work fine, but I would be inclined to ditch the tube rectifier and run some diodes instead 🙂
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I'm going to try it both ways. My Kondo clone will use a tube rectifier, my Shindo clone will run some SS diodes instead.
Furthermore, it's about time I finished them, in fact I'd like them both in use before the end of this year.
Furthermore, it's about time I finished them, in fact I'd like them both in use before the end of this year.
Great incite, that's something I did not consider, "the shared winding". I may just wire up an independent 12v transformer supply or go with the SS route, as suggested by a few. Any issues if I run a Dickson charge pump circuit for the other 6.3v winding, and double it up to 12.6v? Really appreciate all the knowledge everyone has shared on this, if it was not for the forum, this would have probably sat on my test bench for a very long time.
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a voltage doubler is fine if you keep within the power rating of the winding etc. etc.
the HV rectifier tube sits at high potential compared to the rest. It will need 6.3V, supplied by an extra winding in most builds, while the audio tubes need 12.6V , sitting at a different potential. For this reason, and also to avoid noise coupling, I think its best to have 3x6.3V or 1x6.3V plus 1x12.6V windings. Or use a separate transformer (if you have the space).
I had a toroid made to spec by MultiCB, fully potted and with an additional foil around the windings to minimize stray field, almost as good as a mumetal can, cost was €80. It came with 2x115V primary windings as a standard option. Of course, if you want to have something to show off, Toroidy in Poland can provide stainless steel covers for their toroid transformers, looking spiffy! 😀
I had a toroid made to spec by MultiCB, fully potted and with an additional foil around the windings to minimize stray field, almost as good as a mumetal can, cost was €80. It came with 2x115V primary windings as a standard option. Of course, if you want to have something to show off, Toroidy in Poland can provide stainless steel covers for their toroid transformers, looking spiffy! 😀