BasistaFunky Posted August 28, 2021 Share Posted August 28, 2021 Hello there Trace guys, I have a very serious and important question because I need help. I have a Trace Elliot AH130 Series 6 Gp7 amp head see the 2 photos down. The problem is when I turn up the volume to sound louder through my two Trace 4x10 and 1x15 cabinets at 4 Ohms the transistors start to overheat a lot and I am afraid that will damaging the amplifier. The transistors are not actually the original ones and were replaced couple times, So my question is - Can you tell me please where can I find original transistors for this amp to replace the current ones, or if there are no more original transistors anywhere and they are not found wich ones you’ll recommend me to put and repair the amp to work properly and have no more problems? I am urgently waiting for your answer Thank you. Quote Link to comment Share on other sites More sharing options...
BassBunny Posted August 28, 2021 Share Posted August 28, 2021 Get in touch with Ashdown. They are repairing old Trace gear now. 1 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted August 28, 2021 Share Posted August 28, 2021 Ashdown are good guys. You might find the schematic attached on the server at Talkbass in one of the Team Trace threads. Sometimes they misspell Elliot with two tt and one l. Quote Link to comment Share on other sites More sharing options...
Newfoundfreedom Posted August 29, 2021 Share Posted August 29, 2021 Do you mean your two cabs have a total of 4ohms? (i.e 8 ohms each) or that you are using 2 X 4ohm cabs? If it's the latter, then that's why it's overheating. The minimum load of the amp is 4 ohms and running 2x4ohm cabs gives you a load of 2ohms. Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted August 29, 2021 Share Posted August 29, 2021 27 minutes ago, Newfoundfreedom said: Do you mean your two cabs have a total of 4ohms? (i.e 8 ohms each) or that you are using 2 X 4ohm cabs? If it's the latter, then that's why it's overheating. The minimum load of the amp is 4 ohms and running 2x4ohm cabs gives you a load of 2ohms. 4 ohm Trace cabs are rare. He got them after advertising here so pretty sure they're standard 8 ohms unless modded. 1 Quote Link to comment Share on other sites More sharing options...
DGBass Posted September 1, 2021 Share Posted September 1, 2021 Series 6 Trace Elliot amps like the AH100/130/150/200 and even some of the mighty AH250 amps were based around Hitachi lateral Mosfets. You can't get these new anymore but they do occasionally come up for sale as NOS on some internet auction sites at ridiculously inflated prices. Modern equivalents are still available from a company called Exicon. The units are TO3 packaged and a neat fit for the power amp boards on Series 6 Amps.For an AH130 you likely have a pair comprised of a K135 and J50 Hitachi mosfet. It's probably worth investigating why your amp is getting hot before spending time and money replacing mosfets. They aren't cheap. The rear heatsinks on these type amps will get warm running at 4 ohms for extended periods but shouldn't get hot enough to blow mosfets. It would be prudent to check both your cabs aren't running at less than 4 ohms ( most standard wiring on older trace cabs was alway 8 ohms per cab). Also, the thermal compound on the heatsinks on these type amps will dry out after many years service and striping them down, cleaning and re-applying new thermal paste to the heatsink components can cure many overheating and cutting-out issues. If I had one of these for service, I would renew the thermal compound on the heatsinks as a matter of course. I've added a pic showing my own serviced AH200. It still has the Hitachi mosfets intact and working perfectly. I run my cab at 4 ohms and it barely gets warm even after a three hour gig at high power levels. The AH130 will likely just have one pair of mosfets so probably will run a bit warmer with two 8 ohm cabs. 2 Quote Link to comment Share on other sites More sharing options...
Stub Mandrel Posted September 2, 2021 Share Posted September 2, 2021 It could well be that the bias voltage for the power transistors hasn't been changed and they may be running a high quiescent current. I had a similar issue with one of the pre-power stage transistors drifting out of spec with the result that the cones were displaced by the DC offset and the amp ran hot. If the transistors are hot but the heatsink is only warm, could be the thermal compound wasn't replaced when transistors were changed. All should be easy for a competent electronic repair shop to fix, or at least provide reassurance. Quote Link to comment Share on other sites More sharing options...
BasistaFunky Posted September 4, 2021 Author Share Posted September 4, 2021 On 29/08/2021 at 01:08, BassBunny said: Get in touch with Ashdown. They are repairing old Trace gear now. Really are you sure about this they can repair my Trace head? If it’s true Can you please tell me where can I find them service repair in UK? Quote Link to comment Share on other sites More sharing options...
BassBunny Posted September 4, 2021 Share Posted September 4, 2021 1 hour ago, BasistaFunky said: Really are you sure about this they can repair my Trace head? If it’s true Can you please tell me where can I find them service repair in UK? They announced on social some time ago that they were repairing TE gear which kind of makes sense considering Mark Gooday worked at Trace before it was bought by Peavey. Just contact Ashdown Customer service and have a chat. Quote Link to comment Share on other sites More sharing options...
TheGreek Posted September 13, 2021 Share Posted September 13, 2021 Have you tried here? https://britishaudio.com/collections/trace-elliot-parts Quote Link to comment Share on other sites More sharing options...
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