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Old 7th April 2007, 06:58 PM   #151
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Did I say a lot of offset? No, it's the same but now there is no turn on mute circuit so I get a BIG thump with those 10uf Cerafines.
Not that I care at all...
Before boxing her back up I put some copper shielding over the inputs and caps etc...

This is now the amp it should always have been

Excellent! as good as an amp6 once you have done all that I have

Now for my main amp to finish... come on Lee get a shuffle on
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Old 8th April 2007, 12:04 AM   #152
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Great news & well done!

Can you give us more details about the mute circuit and exactly what you did to it?
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Old 8th April 2007, 12:45 PM   #153
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Quote:
Originally posted by Fin
Great news & well done!

Can you give us more details about the mute circuit and exactly what you did to it?
Hi Fin, don't ask me to explain how the mute circuit works, it also appears to have an overvoltage aspect to it so that's probably why Pano's amp doesn't like 15V.

As far as removal is concerned you just need to remove the wire from the board to break the connection, it draws voltage on one of the wires and returns it to pin 11 on the other depending on the conditions.
I also removed the grounding resistor and the little inductor and just put a bridging wire in there to permanently connect it directly to ground. You leave them in I suppose and just remove the wire.

It really does sing now so I'm listening to it on my main system whilst I get my new amp finished. It's amazing how more 'open' the sound is with far better seperation and staging. I recommend shielding the inductors from the rest of the circuit, I think this also made a big difference, especially in such a small box.
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Old 10th April 2007, 08:46 AM   #154
Pano is offline Pano  United States
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Good find on the mute circuit, Lee. I'll have a look at it.

Wanted to run the chip on 15V for a while to see how it does. Shouldn't be a problem, as the AMP6 runs on 14.5V all day without breaking a sweat. The diode at the input of the Lepai is going to drop the voltage a bit, so I may bypass it.
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Old 10th April 2007, 02:12 PM   #155
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Quote:
Originally posted by panomaniac
Wanted to run the chip on 15V for a while to see how it does. Shouldn't be a problem
Hi Michael, just wondering if you can do that without some extra diodes in there? Maybe that's why it has a protection circuit?

TA2020 datasheet..........
"Diodes (DO and DH) are Motorola MBRS130T3 (the DH diodes are required for VDD>13.5V)"

I changed out the diodes to the recommended ones when two of them failed after being left on for a couple of weeks.
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Old 10th April 2007, 10:22 PM   #156
Pano is offline Pano  United States
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Ah, true enough.

The extra diodes help kill the overshoot on the output transistors. The AMP6 has them. Does the Charlize? I'll have to go look.
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Old 30th July 2007, 03:26 AM   #157
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About half way down the page there is a modded Lepai T-amp.......but the Google translation is not great.......

http://www.maurarte.com/T-AMP.htm

Quote:
This small and amplifier economic (approximately 40 euro sent to house) mount chip Tripath TA2020 that fed to 14V leggermente distributes a advanced power to the TA2024 that equips the T-Amp. It widens is introduced with houses decorous but from the rather approximate finish. The printed circult is of rather low quality but fortunately the members are not in SMD. The scatolotto he has beyond the grip handle of the volume also that one of the bottoms (calls Boss to you!!) and that one of the acute ones. The switch who from the first moment seems a switch of ignition in reality puts in stand-by the member. The sound is not badly, to my warning better dell Amp-6 than 41HZ that it mounts the same one chip. The bottom is deep and fast, the scenica reconstruction is rather good, appreciable dynamics, but to my warning the medium range loses something in comparison with the T-AMP. Seen the good accessibility to the circuit the modifications in order to improve it have been innumerevoli. The objective was to improve the quality of the medium range and to render the behavior of the scatoletta still more dynamic. The Lepai mounts in income operational (a RC4558) a lot used in the effects for little indicated guitar but for applications Hi Fi. The first participation has involved the assembly of one hoof for IC and the istallazione of a NE5532 a sempreverde economic but from the good performance. The successive step has been the substitution of all the elettrolitici presents in series to marks them (8 from 3.3uF) with Wima.Successivamente polyester has eliminated is the diode valve anti polarity reversal that the inductance in series to the feeding and I have replaced the condenser of feeding from 2.200uF with a Elna low ESR. Not content I have replaced the two condensers from 100uF present in the immediate vicinities of the chip with others from 1000uF. The final touch has been that one to replace the inductances of the ricostruttore filter with wrapped others in air. To the end of all the job the quality of the small widens is improved very many above all in medium range where it is increased to the selettivitą and the precision of reproduction of the instruments. I have intentionally maintained the tone controls because to my warning the advantages that carry are by far advanced to the small imputable sonorous degradation to they.
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Old 31st August 2007, 02:12 AM   #158
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what is the bottom line on this amp?, gather cheap, and with proper mod sounds good. Is this correct?

1. where does one buy the unit?
2. is there a picture of mod?, step by step, pano?

seems like the picture of the unit is hard to come by.

gychang
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Old 31st August 2007, 03:43 AM   #159
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there was one on ebay I found yesterday, but lost the link, but under the guise of a bike PA?...
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Old 31st August 2007, 06:40 AM   #160
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Quote:
Originally posted by gychang
what is the bottom line on this amp?, gather cheap, and with proper mod sounds good. Is this correct?

1. where does one buy the unit?
2. is there a picture of mod?, step by step, pano?

seems like the picture of the unit is hard to come by.

gychang
I modded mine to the point were most of the board became redundant, to that end, its quite a big box for a small amp!
There are quite a few pictures and diagrams of what to do further back in the thread but not one collectively.
I would recommend bypassing the entire input section and wiring it in (in-air) through new resistors and caps, replace the power caps and use either a new quality pot or one for each channel.
IF you can find one for the right price that is... an amp6 is better and cheaper in the long run otherwise......
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