Trace Elliot AH1000-12 schematic needed

[Jazz P Bass]

"Reasonable 2 hours continuous output power test?"

Say what???

Believe it or not, for test purposes, you do not need to beat the piss out of the amp like that for that length of time.
50% power output is probably harder on the amp.

Unless maybe you are doing a current limit test ala QSC.

[Roberto]

Perfect, so 600 W total will be enough, and water can go down to 15 liters: even better to be moved.

[J M Fahey]

FWIW I use sections of standard "spring" type heating elements, eyelet/riveted to strips of Micanite (remanufactured Mica sheet) , which allows me to get *exact¨* resistance value needed, then drop such load resistors inside a bucket of water 1 or 2 meters away from bench, so even if it boils, no big problem.
B esides being dirt cheap, they allow me to get off resistance vaalues at will, such as 6.6 o 5.5 ohm, which are typical real worldspeaker DC resistance values.
Excellent to test protection circuits .

[Roberto]

I'm just back home from a long trip, while I've found some solutions:

Substitute the modules at 60€ for both, and sell the working one:
2x https://www.ebay.it/itm/121370148870

Substitute the big toroid and final modules with those (small toroidal for the 12AX7s) at 120€ for both modules and resell the working module plus the toroid:
2x https://www.ebay.it/itm/172546989166
2x https://www.ebay.it/itm/282836152610
https://www.tube-town.net/ttstore/Tr...7VA::5391.html


Substitute the big toroid and final modules with those (small toroidal for the 12AX7s) at 115€ and resell the working module plus the toroid:
1x https://www.ebay.it/itm/142742467613
2x https://www.ebay.it/itm/282836152610
https://www.tube-town.net/ttstore/Tr...7VA::5391.html

[Roberto]

https://icepower.dk/products/amplifi...les/as-series/

They replied to me today: they do not sell directly, and the AS series cannot be sold in small numbers even from their partner site.

[Roberto]

I've found a cheaper option to keep the toroidal and have the mono and stereo capabilities:
Run the two windings of the PT in parallel to this bridge rectifier (GBPC50: 1000V 50A 1,1V drop), that costs 4 €:
https://docs-emea.rs-online.com/webd...6b80dadbc2.pdf

Then this module that costs 100 €:
https://www.ebay.it/itm/142730977129
Running stereo at 500 + 500 W on 4 + 4 Ohm or mono bridged at 1000 W on 8 Ohm.
Two fans and an air filter will be added as well.

And of course resell the two modules.

[glebert]

Note you also need a low voltage (6-12V) AC signal to that power module as well.

[Roberto]

Thank you glebert, yes they told me 12-0-12 Vac or 15-0-15 Vdc.
I'm waiting a reply about the needed current (that I think would be low), in order to see if I can use the PSU already present in the preamp (15-0-15 Vdc).

[Roberto]

Ok, I finally came out with the following solution:

1x https://www.ebay.it/itm/142742467613 @ 61 € shipped
1000 W power supply with custom:
+-70 VDC for the power amp
+-15 VDC 500 mA for the preamp and the heaters of the preamp tubes (in series with 33 Ohm, so something less than 150 mA for them)
+12 VDC 500 mA for the fans

1x https://www.ebay.it/itm/172833474016 @ 67 € shipped
1000 Wrms @ 8 Ohm power amp (if bridged, capable to run stereo as well as the original amp)
Needs +-70 VDC plus +-15 VDC

1x https://www.ebay.it/itm/192074192680 @ 20 € shipped
Toroidal transformer 50 VA
Pri 0-230 VAC
Sec 0-200-260-290 VAC 180 mA (one secondary with three taps to try three different B+ for the 12ax7s)

Total will be 148 €, and I'll have the original toroid and two modules (one working, one not) to sell, plus I'll save 22 kg of weight on the amp.

Do you guys see something technically wrong in this solution?
Thank you for your feedback.

[Roberto]

An update on the topic: as a load to test the power amp I've found this water heater:
https://www.ebay.it/itm/361962587631

It has three elements in parallel, 2 kW each at 230Vac, so that the three in parallel give 8,9 Ohm.
13 euros shipped.

[nickb]

It says it'd 380V so 380^2/6000 = 24 ohms. You need to buy three of them.

I saw these 220VAC 6KW ones. They would be 8 ohms.

[Roberto]

My interpretation of its declaration is different, but I've asked to the supplier to better specify.

380 V is sqrt(3) * 220 V, so the old EU three phase standard voltage.
This should be confirmed from the fact that there are three units in parallel (one for each phase).
This would mean three resistor in parallel of 2 kW each, means three resistors of 26.45 Ohm each (because between each phase and neutral there are 230 V), so 8.82 Ohm when connected in parallel.

[Roberto]

Now I know how they are connected usually.

[nickb]

Ah ha!. Well that's worth knowing.Thanks for the info.

[Roberto]

Thanks to you for letting me think more about it.
Even the seller was not able to answer me, I've used google images to find another seller's instructions.
I'll go with this one: https://www.ebay.it/itm/401314483971