Hartke HS 1200 bass amp transformer needed

[detoxic]

Does anyone know where I can get a transformer for a Hartke HS 1200 Bass Amp?

Thanks

[The Dude]

Welcome to the place!

Contact them directly. Here's their support page.

Support | Samson Technologies

I have to ask......What makes you think the transformer is bad? Transformers don't fail all that often.

[detoxic]

the thermal fuse inside it is blown and the 220V section of it has a short in the coils. It might be possible to run it on the 115V section of the transformer but Im in Hong Kong with 220V so would need to use an exterior transformer down to 110V.

[Enzo]

Make sure to point out your location to them, and ask where you can source the part in your part of the world.

[J M Fahey]

Absolute worst case, post the schematic here, SS equipment is relatively generic and if the original transformer is unavailable very probably other easier to find can be fit there.

Only doubt: do you have ample Electronics parts available close by (EBay made us believe *anything* can be sourced from HK) or you still should have to buy it in USA (assuming Hartke can't give you a local solution).

[detoxic]

hartke_hs1200_sch.pdf

It seems this transformer is made specifically for this amp - having dual coil outputs with different voltages so I believe Hartke might be the only source. I have emailed and waiting for their reply. Yes there is a huge amount of electronic parts available here in HK and even more just across the Chinese boarder into Shenzhen. I may have to take the transformer there to see about sourcing depending on Hartke's reply.

Thanks for your help
Cheers

[Enzo]

Transformers for solid state amps usually have a winding for the main rails and one for the low voltage. Since the low voltage is almost always 15v, that leaves the main rails, which tend t be similar for similar watt ratings. So a transformer from some other brand of similar amp might well fit.

[J M Fahey]

[ATTACH]35456[/ATTACH]

It seems this transformer is made specifically for this amp - having dual coil outputs with different voltages so I believe Hartke might be the only source. I have emailed and waiting for their reply. Yes there is a huge amount of electronic parts available here in HK and even more just across the Chinese boarder into Shenzhen. I may have to take the transformer there to see about sourcing depending on Hartke's reply.

Thanks for your help
Cheers

Please repost the schematic but first ZIP it *or* change its name (say, Hartke1200S-reposted.pdf) or upload it somewhere accessible and post the link here , because it was posted here before , the server crashed, the file was lost but the system does not allow a new file with the same old file name and size.
As is, the file comes down "empty".
Thanks.

EDIT=
just found it in Elektrotanya :
HARTKE HS1200 SCH Service Manual free download, schematics, eeprom, repair info for electronics

anyway, for easier display on this page, I converted it to .GIF


The schematic shows two sets of windings, higher voltage for the power amp and lower for the preamp, they can be calculated:
Power amp, 120W RMS/8 ohms= 31V RMS ; call it 32V because Hartke is conservative in its ratings.
That means rails about (32V *1.41)+4V (transistor loss) * 1.15 (to account for transformer drop) so about +/- 55 or 56V DC, which means transformer windings about 56*.707=40+40VAC @ 2.5A or better .
Or the transformer might be specified as 36+36 to 40+40 VAC , some 180/200VA or better.

The low voltage winding is not very critical, since preamp consumption is low and voltage is regulated, but 16+15VAC to 18+18VAC at 300 mA or better will do.

So with those specs you can go hunting.

Is it a toroid or an EI transformer?

This one by ANTEK is a beast of a transformer, way over specified (specially the low voltage winding) and will do very well, only problem is that it *might* not fit in available space:
AS-3440 - 300VA 40V Transformer - AnTek Products Corp

[Enzo]

I have had that model through the shop, but don't recall, however I don't recall the last time I saw an EI transformer in a Hartke.