trinityamps.com

Jac. Sounds good. I wish I could get my girlfriend to help out on this stuff. Occasionally I'll have her feed the solder if I need 3 or 4 hands to hold something.

You're right Stephen. I sould go for the West Labs stuff. There's no point in spending all this time and effort if I'm just gonna go and cut a corner.

A couple things about the West Labs transformers... Why don't they list the secondary widing specs? And would using a 6V rectifier be much different than a 5V one? Or should I forget the tube all together and go with solid state diodes? The money I save on glass over the years will pay for the difference in price compared to hammond.

Bradovka -

If you go with solid state rectifiers, you'll need to get a lower secondary voltage on the PT. I don't have a firm enough grasp on the math involved to have confidence in my numbers, but the AX84 5-watt single ended project specs a 250-0-250 PT and produces B+ of 325 at the first node: AX84 poweramp schematic It's intended to be a basic 5 watt amp with one 12AX7, one 6V6, and solid state diodes for rectification - darn close to a 5F2-A to me. The 60ma rating on the high voltage secondary might be a bit low however.

Didn't know that Westlabs sold transformers. All of their other stuff is top quality (if a bit pricey). Anybody know which company actually makes them? It's whoever made the last batch of trannies for Matchless...

Chip

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noob de lux

In addition to Partsconnexion there's Electrosonic in Toronto but the best prices I've found for Hammond stuff north of the 49th is Tip Top Electronics in Winnipeg (and no pst for those outside the province). With px you need to check the exchange rate (they price in $US) and also add in pst. E-sonic is more expensive to start with on the Hammond's plus you pay pst. Tip Top usually takes a couple weeks for non stock items but I've had the same wait time for non stocked Hammond transformers from E-sonic. (E-sonic carries Mallory 150's.) Last time I checked, px had good looking prices on the Hammond's but you always need to do the math.

Seeing as this is my first post I have to put the links in my next post.

Take care
dave

Here's the links for my above post.

http://www.partsconnexion.com/

http://www.tiptopelectronics.com/

http://www.e-sonic.com/acc/home.aspx

Aren't tabs great.

dave

If you look at the Mark Huss Champ Beast schematic he uses the Hammond 270DX and 125ESE transformers.AX84 uses these transformers in their SE P1 Extreme project.Just look at their schematic.

The Hammond 270DX is rated 275-0-275v , 90ma. Good luck with whatever you use. Looking forward to seeing your results.

Rectifiers in SE--in principle they should only effect the voltage, as the output tube is always drawing current. The reason people have preferences for different sorts of rectifier tubes is about fine-tuning the voltage. I think the NOS will drop more volts than a Sovtek 5Y3, which I understand is closer to a 5V4. I don't know about the six volt rectifiers. You can always fine-tune voltage drop with an appropriately rated resistor in the supply--it's a common mod when using solid state rectifiers.

Bear

I sent Dave at westlabs an email. They've just posted some new "Lo Power" 250-0-250 Volt 100 Ma transformers. They look perfect. Set of power and output for 100 bucks.

Did he say how many amps on the heater winding? Can't imagine you'd go over capacity with one 6V6 and one 12AX7 but you never know...

That sounds like a relatively good deal $$$ wise. I paid $100 incl. shipping for a Hammond 270EX PT and a custom Heyboer OT rated at 20 watts from Doberman (the AX84 host).

Chip

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noob de lux

Not sure what the amperage on the heaters are, but I'm assuming they had 2 tubes in mind when they built 'em. The website says they're for AC4's and Princetons.

I'm still waiting on another email so maybe he'll mention it.

Information from the westlabs site:

The 7 watt set is the same as the Lo Volt watt set except the power transformer has a higher B+ voltage thus the 7 watts! They were built in the same factory and to the same quality as the Matchless transformers. They are designed for ONE EL84, 6V6, or 6L6. The power transformers have no 5 volt winding for a rectifier tube. It is designed to work with a 6 volt rectifier tube like a 6V4 or a 6CA4 as in a Vox, OR Solid State Diodes!

All four power transformers have super duty current delivery capability and are not likely to be overloaded regardless of the number of preamp tubes in your circuit.

I hope that helps.

Well that sure clears it up. I've read that page a few times now... Maybe just not all the way through!

3.8 amp 6.3v filament supplies for both the high and low voltage PT, or at least it was when I inquired as to spec. You can run a fair number of tubes off of that.
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