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Transcendent 2000 Powertran PCB diagram

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Re: Transcendent 2000 Powertran PCB diagram

Postby Folderol » Wed Feb 18, 2015 1:08 am

Changing R80 and R81 might be helpful, but I wouldn't recommend altering the other components. However, before that, try unplugging IC22 (the VCA). If the noise is still there it's probably the final 741 gone noisy.

If it goes quiet, then it's definitely the VCA stage. R82 is a possibility, being a very high value. If it's the LM3080 itself you might have a bit of difficulty finding a reliable source for a replacement.

To confirm whether it is the chip, it might be worth swapping it with IC19, and set the shape switch to BP (this takes the IC19 position mostly out of the signal path).
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Re: Transcendent 2000 Powertran PCB diagram

Postby midierror » Wed Feb 18, 2015 10:38 am

In hindsight, I think I took the recording from the LOW OUT :shock: I took the IC 22 out anyway but it didn`t do much so I think it`s all in order.

BUT!! Replacing those 10k resistors gives an 8dB boost to the signal, with no noise increase! Highly recommended. Folderol, are you sure replacing the others won`t help?
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Re: Transcendent 2000 Powertran PCB diagram

Postby Folderol » Wed Feb 18, 2015 10:05 pm

Well that's good news then. As a matter of interest, if you have a TL071 knocking around try putting it in place of that last 741, IC21. They are very much quieter.

C26 with the associated resistors (including the pot) will give you a -3dB point somewhere near 22Hz, changing it for 470nF would bring that down to about 5Hz so you'd be likely to get a lot of sub-audio junk being passed through with every key press! There are other caps in the signal path that give additional high pass filtering, (all around the same frequency) but I still don't think it's a good idea.

Changing R82 to 10M would reduce the control range of RV22, but then as you've effectively increased it by changing R81 that might not be a bad thing. You want to be able to adjust it a little either side of optimum.
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Re: Transcendent 2000 Powertran PCB diagram

Postby midierror » Fri Feb 20, 2015 9:07 am

Yeah the guy mentions that the 470nF didn`t work too well on that page. I`ll definitely give the 10M resistor a go, and report back.
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Re: Transcendent 2000 Powertran PCB diagram

Postby midierror » Sun Feb 22, 2015 12:48 pm

Replaced R82 and initially couldn`t hear much difference - but it appears to have added 3dB to the signal. Sounds quite punchy now :round1:

I`m going to upload some vids to youtube this week - one of which will be about the tranny... and then one about this synthesizer *smirk*
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Re: Transcendent 2000 Powertran PCB diagram

Postby Wonks » Sun Feb 22, 2015 12:54 pm

:D

I spent yesterday morning de-soldering all the old keyboard contacts. I really can't do any more now until the new contacts arrive.
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Re: Transcendent 2000 Powertran PCB diagram

Postby Folderol » Sun Feb 22, 2015 5:16 pm

Wonks wrote::D

I spent yesterday morning de-soldering all the old keyboard contacts. I really can't do any more now until the new contacts arrive.
Well....
I commend your enthusiasm, but personally I would have been more inclined to further investigate the absence of sound while you still had a partially working keyboard
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Re: Transcendent 2000 Powertran PCB diagram

Postby Wonks » Wed Feb 25, 2015 4:44 pm

I've got 1001 other things to do (that's binary by the way).

Got to wait another 4 weeks. Their last consignment of gold wire was all 'crinkled' so they've had to order some more in order to make my contacts.
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Re: Transcendent 2000 Powertran PCB diagram

Postby midierror » Tue Oct 27, 2015 11:55 am

I'm back to shamlessly promote my Transcendent 2000 sample pack

http://www.loopmasters.com/genres/81-Synths/products/4309-Sy...

Only possible beause of SOS forum....thanks to everyone who helped me ressurect it!

I hope you get yours working Wonks!
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Re: Transcendent 2000 Powertran PCB diagram

Postby geoffrey1978 » Fri May 05, 2017 7:00 pm

Hey guys I have a powertran Transcendent 2000 that I'm selling (it was my late grandads) it's in good condition for its age but it doesn't seem to be switching on when plugged into plug socket. I don't have a cables etc to plugin for sound but surely if working the power light would come on anyway when switched on?! Would there be a big issue electrically or something simple? I'm only selling it for £100 so I'm figuring it wouldn't cost much to fix?
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Re: Transcendent 2000 Powertran PCB diagram

Postby Martin Walker » Sat May 06, 2017 6:07 pm

Hi Geoffrey, and welcome to the SOS Forums! 8-)

You say this is in good condition for its age, but then go on to admit that it doesn't power up when you plug it into the mains supply.

Now that might be down to something simple like a blown fuse (although strictly speaking you should have the unit investigated before replacing a blown fuse, as the reason for it blowing might be something that results int he fuse blowing again immediately and doing more damage to the internal circuitry).

However, it's far likely to be something that has failed internally due to age, or it could be a soldered joint failing, or fried components... Also, the Powertran 2000 was sold as a low-cost kit, so its build quality could be anything from immaculately professional to a huge bodge, depending on your Grandad's soldering abilities.

Image

The fault(s) might be easy to solve; or they might not, and you could well pay an expert a lot more than £100 to track down the cause of the problem before they can even tell you if it can be repaired economically.

Sorry to be the bearer of bad news, but it's almost impossible for any of us to fault-find by remote control, and you could do yet more damage trying to fix it yourself.

You say you're only selling it for £100, but I suspect since you have no idea just what's wrong that you'll have to sell it as 'not working, for parts only' and leave it up to the buyer to investigate the cause of the problem.

Hope this helps!


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Re: Transcendent 2000 Powertran PCB diagram

Postby tactic mind » Sat May 04, 2019 8:53 pm

midierror wrote:Thanks for the offer, maybe we can assist each other in getting them working? I would love to see scans of the diagram to confirm I havent mis-read anything. I`ll send you my email address now.
hello there i am sorry but i have also problem with my transcendent-powertran-2000 is it possible to ask to get the scan to try to fix my powertran of my please thanks for help my mail is kyo_log@hotmail.com god bless you (:
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