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20to20,

Good for them they call them that, that's not their design purpose on mine. The design purpose is to perfectly simulate the V-drop of a 5AR4 @ bias. Took me testing with every 5% value from 47 to 220 ohms and waiting after a half-hour play each time for warm-up to get it.

Cheers!

Geek wrote:20to20,

Good for them they call them that, that's not their design purpose on mine. The design purpose is to perfectly simulate the V-drop of a 5AR4 @ bias. Took me testing with every 5% value from 47 to 220 ohms and waiting after a half-hour play each time for warm-up to get it.

Cheers!

I woke up this morning and the first thought that struck me was that the Antek not only does not have a bias tap but it doesn't even have a 5v. tube rectifier secondary winding.

Geek,

Were you just trying to build your own 5AR4 replacement, or trying to solve an arcing problem after modifying the amount of capacitance?

[/quote]Here's a link to the specs

http://www.antekinc.com/details.php?p=88[/quote]

My bad, I was thinking of the AN-4TK360 which does have bias taps and, curiously, is not on the Antek website but is on ebay...

http://cgi.ebay.com/720V-CT-360V-400VA- ... ltDomain_0

tomlang wrote:

Here's a link to the specs

http://www.antekinc.com/details.php?p=88

My bad, I was thinking of the AN-4TK360 which does have bias taps and, curiously, is not on the Antek website but is on ebay...

http://cgi.ebay.com/720V-CT-360V-400VA- ... ltDomain_0

Tom,

I went back through the posts and discovered that the discussion started with the AN-4TK360 and got changed (by typo?) to the AN-4T360. Antek should use a different model numbering system for product that is so radically different.

Furthermore, I have read thread(s) where somebody got one of these Antek power transformers and it had one 5 volt and one 6.3 volt winding instead of two 6.3 volt windings!

Finally, last winter I ordered and received two AT-040L output transformers but had to send them back as the published dimensions were much smaller than they were in real life. I just noticed they still did not change it! They are actually over 5 inches in diameter.

Two lessons I learned here: 1. Call and talk to John Ango and verify what you are getting both electrically and physically before ordering and, 2. Always plan your chassis layout after you get the parts.

tomlang wrote:Furthermore, I have read thread(s) where somebody got one of these Antek power transformers and it had one 5 volt and one 6.3 volt winding instead of two 6.3 volt windings!

Finally, last winter I ordered and received two AT-040L output transformers but had to send them back as the published dimensions were much smaller than they were in real life. I just noticed they still did not change it! They are actually over 5 inches in diameter.

Two lessons I learned here: 1. Call and talk to John Ango and verify what you are getting both electrically and physically before ordering and, 2. Always plan your chassis layout after you get the parts.

Antek does have the AN-4TK360 and 400 with bias taps and you can get either a 6.3CT and 5V or 6.3CT and 6.3. Just talking with John might not get you the proper transformer. Twice they sent me the wrong one.

You could probably use a AN-2T350, it'll do 350 volts at 500ma. But you'll need an extra 6 volt transformer. Antek's 6 volt transformers are actually a little under 6 volts. The biggest is 2 X 6V at 4.2A, loaded it is 5.7 volts, unloaded it's 5.9 volts. Just half a volt more would be great. Also Antek's most powerful 5V transformer is a 2 X 5V at 1A.

If you don't have a bias tap, it's easy to make a bias circuit. Have a look at the fixed bias Eiclone, that circuit works very well as I have used it several times.

20to20 wrote:
When do you decide you are not actually building anything like the original?

You mean like this one?

tomlang wrote:

20to20 wrote:
When do you decide you are not actually building anything like the original?

You mean like this one?

Ya man...dude... I want to build an ST-70 buuuut, I don't want to use any of the original parts.... I want to make one that's a hole-lot-better... One that's all transistors and built on the chassis of a Olds Delta 98...

20to20 wrote:Tom,
I went back through the posts and discovered that the discussion started with the AN-4TK360 and got changed (by typo?) to the AN-4T360. Antek should use a different model numbering system for product that is so radically different.

It was not a "typo" on my part; It was a "braino". The link going to Antek's site is to the AN-4T360, which lacks the 70V bias tap. I missed that. The transformer with the tap is the AN-4TK360:

http://cgi.ebay.com/720V-CT-360V-400VA- ... 0683699591

Hi,

20to20 wrote:Geek,

Were you just trying to build your own 5AR4 replacement, or trying to solve an arcing problem after modifying the amount of capacitance?

Replacement

It came about when I was building DynaMutt. Had three 5AR4's on hand, all arcing in this circuit. Tried a Sovtek I ordered for a client and it didn't arc. So I did measurements on what a good 5AR4 was supposed to do in an ST-70 and ran with those figures, since the only data on the net that gave voltages, was conflicting (line variance?).

The Sovtek 5AR4 I found even 68uF didn't bother it. nevertheless, I keep the capacitance no higher than 47uF after it.

Cheers!

does this tranny work with tubes? others have said the 2 70 volt taps are useless ...it wont work due to 0 volt tap placed between the 2 70 volt taps means one is pos and the other neg. maybe could use 1 of them?
actually for stereo mono blocks maybe that means they could have 2 -70 volt taps....just use them from each others sides...and they went on saying the 5 volt taps wouldnt work for a rectifier tube. shoog sed they were wired wrong. true or false? i dont want to fry my new parts...and have the antek 2 x 360v, 2 x 70v, 1 6.3v, and 1 5v tap. AN-4tk360....cant it work for say a st-70 style amp?