teac AL700p center card

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someone gave me a center unit that was taken out of the box of a Teac AL700P. can someone guide me how to put it into use?
seems like the board needs 5V for logic, 12V for relays, and 28V for amplifier. there seems to be some input other than signal - power_on, speaker_on and protect - what are these (12V?)? how to drive them?
And - what PS is recommended (for each type of voltage)?
on the original box, the PS had 5V regulator on both the PCB of the PS and on the main board - the one that holds the channel amplifiers - why?

I know that's a lot of questions, so if there are answers somewhere on the web - please point me to it. searching the forums yielded very little.
 
Schmulik,

Did you ever get the extra Teac board running?

I am trying to do the same but can't figure out what to do with the - power_on, speaker_on and protect pins. I have 24v and 5v to the board but can't get it to "turn on".

Any help will be appreciated. The 2050 can sound great so the effort should be worth it!

Thanks!

Ron
 
I have got a whole Teac AL700P that I am part way through modding. I will need to check again, but I think that the main board (into which the unit you have locates) needs 24v, 15v and 5v. I am going to make up another PS for it and remove the SMPS.

Is there no schematic anywhere for this ?
 
I have totally modded the heck out of my Teac A-L700P. It uses a Jensen 10,000uf 40v for the main power supply cap and Jensen oil 2.2uf cooper coupling capacitors. Inductors were upgraded. The input resistors were changed from smd resistors to riken-ohm resistors. The output filter supply was hard wired with new caps and mills resistors to tripath specs with the speaker relays bypassed. I wish I could take pictures to show you how everything is hook up. Here is a diagram I used for turning the amp into battery power.

You do not have to worry about powering the relays since you are bypassing them, but you need to power the protect-on, speaker-on, etc. My millimeter reads them at 3.5v, but I think you can get by with 5v. There is a 5v regulator on the main board which I power with one of the 12v batteries. When the amp is powered on, the batteries connect in series to produce 24v and parallel when charging.
 

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The rectifier is the voltage regulator. You need to send the 12v to the line in which I think is on the left pin. Check with a multimeter to make sure! The ground is the middle pin so test the voltage on both pins to make sure which is the input and which is the output.

The schematic is confusing, and I thought it wouldn't work, but works like a charm. When the batteries are charging they are hooked in parallel which feeds the -24v of the battery to the regulator, but when the switch is engaged to on, the line turns to a 12v line. I hope this helps.
 
tripathdude,

I have your battery supply wired up and working. Thanks for this!

I want to use it to power the "extra" board as a second amp. Can this done, i.e. can it be used without the main board?

I would love to see a picture of your amp. If at all possible, please post one!

I have modded mine some but still use the smps (with larger caps). I run the input straight in (removing the small input caps) through 2.2 uF Auricaps and use a 35V BG on the amp board.

I think this amp sounds great.

I want to try the battery supply but was hoping to wind up with two working amps to compare. If this is not possible, I will replace the smps on the main unit with the batteries and would love to see your layout.

Thanks for your help!

Ron
 
I think the mod is more leaning towards a signature 30 amp since I bypass all the crap in the signal path. I don't know what Vinnie does in his upgraded version 30.2 with the output filter path. I guess it will always remain a mystery until someone reveals the cap values and schematic. I don't care if mine isn't a signature 30, it sounds freaking awesome to me.
I will try to post pictures this week. I used the Teac chassis with the main board since I can fit two 12v 5ah easily in the chassis. I did build an AMP9 from 41hz recently and compared the two amps. The AMP9 comes pretty darn close to my fully modded Teac and the AMP9 only has upgraded BG power supply capacitors. Everything else is stock. It's a pretty impressive amp and even produces more power and bass than the Teac. I wouldn't mine modded some of the Teac amps for you. I also have some copper heatsinks that fit the TK2050 chip perfectly if anyone is interested.
 
tripathdude,

How much of the difference between your two tripaths do you think is due to the power supplies? I'm assuming the 41HZ Amp is not on batteries. Did you build an AMP9? I thought the 2050 was in the AMP4.

I was hoping to compare battery, smps and linear power supplies. Having the daughter board function as a second amp would be useful and I still think it may be possible.

The amp board seems pretty complete to me. The inputs and outputs are easily accessed, the 24v and 5v hookups are also clear. It's just the power_on, protec, etc. headers that I can't figure out what to do with. It seems to me that all they do is turn the power "on". I am electrically naive, however, and just trying to guess the logic of it.

I have a schematic but can't really read it but would be happy to email it to anyone who could help.

I am still very interested in seeing your pics, tripathdude. What speakers/sources are you using? I'm sure your amp sounds great.
 
bundee. I have modded this amp apart from the power supply. I will need to take it apart to photograph it. Which mods are you wanting to do?

I did the following (if my memory is good)

1. Removed the centre board.
2. Removed the channel volume controls and hard wired the connections
3. Up-graded the input caps

There was a very big thread about modding this amp on Headfi forum about 2 years ago
 
I have been wracking my brain to try to remember where the mods were set out in detail with pics. Got it!

http://www.tommytube.com/Teac-tripath/a_tour_inside_the_teac_a.htm

The pot mode shows how to hard wire the stereo input which is underneath the board. I didn't really want to take mine all apart to photograph the underside of the board.

If you still want me to send pics or need any other advice let me know
 
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