Need help finding an OT

[jon]

I am looking for a small (1-5watt) single ended OT with the following specifications:

3.5K primary
8 ohms Secondary

[Phil_S]

Maybe here....it can be tedious and he's a bit of an oddball. You might send him a question and you might get an answer. Stuff is cheap enough to take your chances.
http://www.oldradioparts.com/2a23dfl.txt
I see maybe:
Stock # *1521-431 Triad S-41X
Stock # -1521-437 Merit A-3031
Stock# 4610-007 Stancor (he says ratio is 22:1, you are looking for 21:1; it's close)
There are a number of universal type, but will be in the 5W range:
Stock# 1417-107
Stock# 4601-149
Stock# 1318-351

[passfan]

I may have one you can have. Ill check when I get home

[passfan]

Nope , 5k and 7k. 3.2 , 8 , and 16 ohms

[jon]

Could I use the 7k primary with an 8 ohm load connected to the 3.2ohm tap. Won't that get me 3.5k at 8ohms

[Phil_S]

No, this requires a constant ratio. You'd need to use a 16 ohm tap.
3500:8 = 437.5
7000:16 = 437.5

Edcor has a 15W 3.5K:8 here http://www.edcorusa.com/p/491/xse15-8-3_5k.

In the 10W model, they also have 3K:8 and 4K:8. All the Edcor's are very affordable.

Musical Power Supplies has OT8SE that offers 7K:16 as an option, which is conveniently also 3.5K:8. This is an 8W model. http://www.musicalpowersupplies.com/products/ also very affordable.

[jon]

Cool thanks Guys

[martin manning]

Nope , 5k and 7k. 3.2 , 8 , and 16 ohms

What's wrong with using the 7k:16 and connecting an 8-ohm load?

[rp]

surely more than you are looking for but here it is anyway:

3.5k Transcendar UL Audio Output Transformers for SE amp, 8 ohm, 10 watt

http://www.ebay.com/itm/Pair-3-5k-Trans ... 41757b1ea6

[jon]

As it will be driving only a reverb tank yes it is a little much

[Richie]

maybe this?

http://www.ebay.com/itm/OT8SE-Tube-Outp ... 258015c3bd

[Structo]

http://www.edcorusa.com/p/491/xse15-8-3_5k

[renshen1957]

I am looking for a small (1-5watt) single ended OT with the following specifications:

3.5K primary
8 ohms Secondary

Hi,

Hammond 125A is a 3 Watt transformer and can be wired 3k to 8 ohm or 3k15 to 6 secondary. But its expensive at $33.00 USD. The 5W 125B is $36.00. I know the literature now states PP but these were the Universal transformers and used as SE until the more expensive 125SE series came out. CEDIST has a 4k to 8 ohm PP that is $15.95. It's an 8W transformer, but most PP are smaller.

Best regards,

Steve

[Leo_Gnardo]

As it will be driving only a reverb tank yes it is a little much

Reverb transformers available from Antique/CE P-TF22921.

Don't sweat the ratios & frequency response etc, it's not a big deal in this application. Just gotta shake the springs. Save those Edcors for hi fi, or a Champ-like amp. Way overkill for spring shaking.

[Firestorm]

Slight derail: what if one wanted to drive a reverb tank using both sides of a 12AT7 push-pull without buying O'Connor's proprietary iron? Any thoughts?