You can be a step ahead here as posted in detail. Measure your mains voltage over a week. The devices were introduced in 2012. Then we had 230V with only small deviations. Not affiliated to any brand but solution oriented in technical stuff. Sorry.
BTW I see some larger toroid types are not produced anymore. This was already noticed with small power open toroids.
BTW I see some larger toroid types are not produced anymore. This was already noticed with small power open toroids.
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Looks like AN-3236 2x36V was a custom order for these amps, not available for purchase. Looking for alternative. There is the Toroidy TTSA0300 2x36V or the AnTek AS-3435 with 2x35V + 2x15V which I could just leave disconnected (no harm done I believe?).
Yeah found the same. Picture of today's market has quite changed as I can not even find 240V primaries let alone 2 x 35V secondaries versions?!? Anyway when a 230V type is chosen you do well with 2 x 35V.
The standard versions seem to be made now only by a handful of manufacturers and are hard to find. They have gone up in price too. Since it seems to become costly anyway you could have 2 wound custom completely to your likings 🙂 For instance with 240V primary (with a 250V tap) and 1 x 72V secondary and screen. Possibly ZM can comment if 1 secondary will do.
Before someone else mentions it: you could use an SMPS 😀 Oddly these can be found in abundance in the right output voltage with abundance of power. Totally independent of mains voltage too.
The standard versions seem to be made now only by a handful of manufacturers and are hard to find. They have gone up in price too. Since it seems to become costly anyway you could have 2 wound custom completely to your likings 🙂 For instance with 240V primary (with a 250V tap) and 1 x 72V secondary and screen. Possibly ZM can comment if 1 secondary will do.
Before someone else mentions it: you could use an SMPS 😀 Oddly these can be found in abundance in the right output voltage with abundance of power. Totally independent of mains voltage too.
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Thank you. I will order the AS-4435 400VA 2x35V 2x15V and leave these last 2 disconnected. The same is done in the SIT4 with the AS-4450 400VA 2x50V 2x15V. Will post back when the amp is back singing.
I still think back on those 2 hours I had with the amps… I was melting in my chair the sound was so good.
I still think back on those 2 hours I had with the amps… I was melting in my chair the sound was so good.
Before I get lost in internet searches for a thingy to log mains voltage over the course of a few days or weeks, can you provide any links to existing data? The last few times when I checked mains voltage during tinkering in my workshop and labs, it was always within 228...235 VAC in Switzerland (numbers from my memory).
I already wrote, post #52 - it's effectively just one secondary, amp practically made with single rail PSU
Now, I can't recommend any Donut Factory outside my small neck of wood, not having proper xperience with any
in past, I did ask my local winder guys (great work, and guyz are having their own High End production of tube amplifiers well known abroad), are they willing to produce and send abroad...... and they said flat no .... simply because of involved paperwork, Serbia not being part of EU and exporting procedure is a must
I wanted them to help EU Greedy Boyz, simply because their work is bespoke; I'm ordering custom Donuts from them and I'm getting proper drek -silent and cold, even feeding heavy A Class load with hefty Cap Bank; and, quite convenient, small ones are blameless in my preamps, same good in case as they are mounted in other room
Toroidy -they're nice and shiny, but I've read in too much occasions here about them working scorching hot..... and if that's true, something is fishy; what, I simply don't care
anyhow, I don't wish to note my guyz in public, not having their consent
what I can is to give you details via PM and you can write to them asking about possible order. If they say yes, all you need is to give pry and sec voltage and say to make it per usual ZM's specs.
Did you just make an offer OP can’t refuse? 😉
BTW I also meant comment on the 240/250:72 300VA with screen suggestion.
BTW I also meant comment on the 240/250:72 300VA with screen suggestion.
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I‘ve bought a number of custom-ordered transformers (TTSA) from Toroidy over the years; have always been happy with them. Didn‘t notice heat problems.
Regards, Claas
Regards, Claas
even better; I wrote what I got as impression from sorta negative writings here ......... not my personal experience
Update. The 35V transformers arrived, are installed and the amps are running. I am back here for advice on an issue.
With the 35V transformer, which was intended to replicate the 101 Vdc of US/EU 115/230Vac SIT1 models, I cannot get the Operating Point meter past the midway point, even with the bias dial adjusted all the way clockwise. That's no fun 🙂.
When running on 100Vac in Japan these amp channels would see 110Vdc opposed to the 101Vdc of the US/EU models. I refer to this as the "design target", e.g. how the amps were tuned and released. See table below.
Advice needed: I believe the best option is to run these amps at 110.1V as per original design intent of these channels. Everything was adjusted based on this operating voltage. The would require 38V secondaries for my local 238Vac. I would much rather do this then to start adjusting parameters within the amp. I have noticed some of the resistors in the resistive load network that set the Vds and Ids are not populated, likely to set the OP where it needs to be at this 110v. The PASS-SIT-1 parts may even have been selected for this voltage, who knows. Net, these amps are tuned to run at 110v, and so it should run at 110v.
Appreciate a thumbs up or small reply if this plan makes sense. It means I will have spent $200 on redundant 35V transformers but who knows, I may use them in the future for a different project, so no worries.
With the 35V transformer, which was intended to replicate the 101 Vdc of US/EU 115/230Vac SIT1 models, I cannot get the Operating Point meter past the midway point, even with the bias dial adjusted all the way clockwise. That's no fun 🙂.
When running on 100Vac in Japan these amp channels would see 110Vdc opposed to the 101Vdc of the US/EU models. I refer to this as the "design target", e.g. how the amps were tuned and released. See table below.
Advice needed: I believe the best option is to run these amps at 110.1V as per original design intent of these channels. Everything was adjusted based on this operating voltage. The would require 38V secondaries for my local 238Vac. I would much rather do this then to start adjusting parameters within the amp. I have noticed some of the resistors in the resistive load network that set the Vds and Ids are not populated, likely to set the OP where it needs to be at this 110v. The PASS-SIT-1 parts may even have been selected for this voltage, who knows. Net, these amps are tuned to run at 110v, and so it should run at 110v.
Appreciate a thumbs up or small reply if this plan makes sense. It means I will have spent $200 on redundant 35V transformers but who knows, I may use them in the future for a different project, so no worries.
Being able to have exactly the right operating point is not a failure nor an issue but seems more or less a desired feature (I thought it was also load dependent?). Having the exact right voltages won’t likely not do much for its 5W output power either. So what do you want to achieve? The circuit is rudimentary as can be, is it that you want to have the needle in the middle with the bias potentiometer in the middle?
Probably not worth to put another 200 Euro in. You could just use it for many years to come.
Probably not worth to put another 200 Euro in. You could just use it for many years to come.
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PS I would see the US/EU 100V DC as leading instead of the Japan only 110V. Maybe just 1 resistor has an other value to compensate for 10V overvoltage and the transformer “trick”. That is way cheaper than having custom 100V mains voltage transformers wound for a few amplifiers to be sold in Japan. If you care about having japanese settings the amplifiers had better stayed there 🙂
Yeah, have the needle in the middle (without adjusting trimpots) so that I can go up and down in 2nd harmonic and see what is the impact to the sound. This is the key feature of this amp and what makes it special.
Enjoyment for years to come is a given.
I did not realize Japan ran on 100Vac, I had thought 115Vac, hence the existence of this thread.
what is important is that you have voltage present at caps in cap bank under their rated voltage; if that's the case, all good; by memory, present voltage at them is in range of 90-95Vdc
now, if that criteria is OK, all you need is to set front button at 12h (mid position) then fiddle with trimpot labeled P1 inside of amp, to get needle meter needle in mid position
et voila!, amp is set; P2 trimpot inside of amp is needle meter setting and that's already set either in FW or PL; that fact being your standing point to do what I wrote in above lines
now, if that criteria is OK, all you need is to set front button at 12h (mid position) then fiddle with trimpot labeled P1 inside of amp, to get needle meter needle in mid position
et voila!, amp is set; P2 trimpot inside of amp is needle meter setting and that's already set either in FW or PL; that fact being your standing point to do what I wrote in above lines