ST35 chassis prototype

[Blair]

I have one of those Antek toroids, 275 - 0 -275 volts.

Where are people finding these Antek 275-0-275 toroids? All I seem to be able to locate are the 500CT and 600CT models on eBay.

antekinc.com is the website for John Ango's toroids. He is a nice guy, but has made more of a practice now of only offering certain models. He used to wind them to spec. I assume if you needed a few hundred, he may be more flexible though. His trannys are supposidly rated at 20% under their capabilities. They are inexpensive, and are pretty beefy. I'm running two poseidon boards off one 800vct tranny with easy and with only a +/- 6v fluctuation on my B+ even at 3/4 power on 85db speakers. So, all in all, I say he is good for his word.

HTH

Blair

[EWBrown]

Similarly I found through measurement that the 230 + 230 VAC (actually 240+240 VAC) 250VA toroids have an exact 1:2 primary to secondary winding ratio, unloaded, with 123VAC (my usual AC line voltage) input on the parallel-connected primaries, these delivered 246VAC on the parallel-connected secondaries with no load, and dropped only a few volts AC with a 100 watt "light bulb" load. The DCR of the windings is quite low as compared to that of the secondary windings on a Hammond trannie.
Less IR loss, less heat generation, which is a good thing...


I suppose these would make good step-down isolation trannies, as well, and they don't "favor" the lower voltage winding.

FWIW, antekinc.com now redirects to http://www.toroid-transformer.com/

The 450VA rated 360 + 360VAC & 6.3 + 6.3 VAC @ 5A would be a good ST-70 power source! :o :o :o

/ed B in NH

[Vince]

Hi Ed,

[The 450VA rated 360 + 360VAC & 6.3 + 6.3 VAC @ 5A would be a good ST-70 power source! ]
I hate to demonstrate my stupidity, but what is the part number of the transformer you refer to above. I am going to need an ST70 one *very* shortly!
Thanks, Vince

[Blair]

Hi Ed,

[The 450VA rated 360 + 360VAC & 6.3 + 6.3 VAC @ 5A would be a good ST-70 power source! ]
I hate to demonstrate my stupidity, but what is the part number of the transformer you refer to above. I am going to need an ST70 one *very* shortly!
Thanks, Vince

AN-4T360 He offers a shipping fee of only 10 bucks too! So for 55 bucks you can have a pretty nice tranny.

Blair

[Vince]

Hi deicide67,
Can you comment on two things?
1. Can it be intelligently mounted on a stock ST70 chassis?
2. Is it electrically and sonically equal to or better than the upgraded ST70
power transformers available from Troide and Dynaparts?
Thank you, Vince

[Blair]

I don't know about intelligently, but I see alot of people making wooden H brackets and mounting the toroid between them. If you were to make it wide enough with wood, you could even use the standard bolt holes, and wood screws to fasten it.

HTH

Blair

[EWBrown]

He's got 9 of 'em availabl on e-bay "buy it now" for 59$

http://cgi.ebay.com/720V-CT-360V-400VA- ... dZViewItem


You can get more specs off the toroid-transformer site. AN-4T360

E-bay price is $59, and the home site price is less.

He calls it "400 VA" but it's really 450VA, 360 X 2 @ 500 mA and 6.3V X 2 @ 5A. and the given current ratings are for 50Hz, at 60Hz they are about 20% higher.

It's far too large for under the chassis mounting, and too wide to mount it horizontally on an ST70 chassis, it has to be "vertically" mounted, with some form of bracket. It won't be real pretty, but it's a co$t savings...

HTH

/ed B in NH

[mesherm]

Those toroids can be mounted something like this.

[Vince]

mesherm,

OK that takes care of mounting the toroid (and I bet that would work
on a stock chassis)!!!
But where did you put the OPT's. Or am I blind!!
Thanks, Vince

[mesherm]

[Vince]

Hi Mike,
I emailed the folks in the Netherlands about shipping a pair of these to Northern Ca... haven't heard anything yet.
Is there a US source for something like this? If AnTek makes something I'm not smart enough yet to figure it out.
Thanks, Vince

[mesherm]

I have ordered 3 pairs of those Amplimo 3A524 OPTs before right from the website. 48 Euros plus about 30 shipping it takes about 2 to 3 weeks but before you get any realize that thet have no UL taps so you have to run your tubes in triode mode only.

[EWBrown]

Boris Sasic, at Audio Vista Engineering, offers the Trafomatic power and OPTs for ST70, ST35, and others. He makes quarterly bulk orders from Trafomatic, (located in Serbia) so the wait may be a few weeks up to a couple months, as he doesn't stock too many items at his upstate NY location.
He has an e-bay presence, just search for "Trafomatic".

The Trafomatics have the proper UL taps.

I have a set for the ST35, but haven't yet put them to work...

You can see what the Trafomatics look like here:

http://www.diytube.com/phpBB2/viewtopic.php?t=1752

The ST35 set is smaller than these, and the OPTs are about 3/4 the size of the power trannie. THey also makes these in the "naked" unpotted / unshielded versions for lower cost.

/ed B in NH