I took it back out of the box to take a closer look at the rest of the unit.
The DAC and surround processing is all on a separate board. The DAC uses a CS8415A receiver and there are 4 CS4391 DAC IC's. I don't think either of those are considered to be junk. It's probably their implementation or power supply to blame for any lack of quality.
I believe one DAC is for DVD, one for CATV, one for front panel optical SPDIF, and one for rear optical and coaxial SPDIF.
The DVD transport is not IDE from what I can tell. It has its own small ribbon cable that goes to the DVD control board.
Every last connector in this thing is clearly labeled. No need to sift through a maintenance manual to figure out what this wire or that wire is for.
The DAC and surround processing is all on a separate board. The DAC uses a CS8415A receiver and there are 4 CS4391 DAC IC's. I don't think either of those are considered to be junk. It's probably their implementation or power supply to blame for any lack of quality.
I believe one DAC is for DVD, one for CATV, one for front panel optical SPDIF, and one for rear optical and coaxial SPDIF.
The DVD transport is not IDE from what I can tell. It has its own small ribbon cable that goes to the DVD control board.
Every last connector in this thing is clearly labeled. No need to sift through a maintenance manual to figure out what this wire or that wire is for.
Maybe the unit sounds "rough" since not adequately burned in? Leave it on for a few nights to see if it sounds any better?
Both of mine seem brand spanking new...never used.
Also may be worthwhile to disconnect all power on cable box board and other non-essential components to test DAC/analog in sound quality - maybe it has something to do with it...
Both of mine seem brand spanking new...never used.
Also may be worthwhile to disconnect all power on cable box board and other non-essential components to test DAC/analog in sound quality - maybe it has something to do with it...
Service Manual
Burning it in may help. Burning is a good term here. Mine generates a LOT of heat. Surprising, as this is a class-d. Even at idle the thing gets pretty warm. Must be all that DSP. =)
Has any one found the service manual? Can we send out a search posse?
I can see a few more reasons why the unit failed. The cable tuner isn't great. Changing channels is slow, and the channel number isn't displayed onscreen. Too bad, as it does a nice job with TV audio.
Burning it in may help. Burning is a good term here. Mine generates a LOT of heat. Surprising, as this is a class-d. Even at idle the thing gets pretty warm. Must be all that DSP. =)
Has any one found the service manual? Can we send out a search posse?
I can see a few more reasons why the unit failed. The cable tuner isn't great. Changing channels is slow, and the channel number isn't displayed onscreen. Too bad, as it does a nice job with TV audio.
Believe it or not Pano, the TA3040 chipset itself generates a lot of heat. I would say more than the mosfets do at idle. I checked the idle power draw of the whole unit and its not too bad, 25-30 watts.
I just had a conversation with someone I haven't talked to in 7 years that knows quite a bit about switchmode supplies. I convinced him to design me a 1KW offline supply with some very interesting technology for me to use on these amps. His free time is almost non-existent, so getting him to do this is like winning the lottery. 😀
I just had a conversation with someone I haven't talked to in 7 years that knows quite a bit about switchmode supplies. I convinced him to design me a 1KW offline supply with some very interesting technology for me to use on these amps. His free time is almost non-existent, so getting him to do this is like winning the lottery. 😀
The weather was perfect here so we went to the lake today, just got home. So the DVD player tests using the RCA & Coaxial cables is going to have to wait until tuesday.
I just ordered some 20k 0805 SMD resistors for adding in parallel with the stock 15k over-current limit resistors. This will fix any over-current trips associated with lower impedance loads.
Anyone in this thread that has ordered one of these receivers and plans on doing any mods to the amp board, drop me an email and I will send you some resistors plus some 0.015" silver solder.
I only ordered 200 peices and 6 are needed per amp board, so supplies are limited.
Anyone in this thread that has ordered one of these receivers and plans on doing any mods to the amp board, drop me an email and I will send you some resistors plus some 0.015" silver solder.
I only ordered 200 peices and 6 are needed per amp board, so supplies are limited.
I was able to do the RCA & Coaxial test with my Toshiba DVD player tonight. I agree with panomaniac that the Coaxial input is a wide effect, it's too bad because I think it would have a very good sound if it didn't have the stereo wide sound. It is still less harsh than the built-in moto DVD player.
The RCA cables to my Toshiba DVD player, that is the WINNER by far!! Much less harshness, and more midrange than the moto DVD player. (Still not like the SI) but closer!!! I'm guessing after some break-in this TA3020 chip will "open" up like the 2024 did. This test is also on moto #2 which is up in my office where the T-amp is, and I have only about TWO hours on moto #2! I have about 30 hours on moto #1 which is in the basement. I just set-up moto #2 tonight. Wow, I'm really starting to get some nice sound out of the moto. The Toshiba with my good RCA's made a huge improvement, I'm pumped! This thing sounds great.
I'm VERY excited about replacing the input caps, I will need help making the right choice!
I think this says that the moto dvd player is not very good for sound quality. I thought that the picture quality was good however on moto #1 in the basement.
The RCA cables to my Toshiba DVD player, that is the WINNER by far!! Much less harshness, and more midrange than the moto DVD player. (Still not like the SI) but closer!!! I'm guessing after some break-in this TA3020 chip will "open" up like the 2024 did. This test is also on moto #2 which is up in my office where the T-amp is, and I have only about TWO hours on moto #2! I have about 30 hours on moto #1 which is in the basement. I just set-up moto #2 tonight. Wow, I'm really starting to get some nice sound out of the moto. The Toshiba with my good RCA's made a huge improvement, I'm pumped! This thing sounds great.
I'm VERY excited about replacing the input caps, I will need help making the right choice!
I think this says that the moto dvd player is not very good for sound quality. I thought that the picture quality was good however on moto #1 in the basement.
Maybe someone can check to see if the DSP-501 defaults the Digital input to a "wide" DSP setting? I remember digging around in the manual a while back and I think it had some DSP settings (hall, theater, jazz, rock, etc) The setting should be on straight through for digital music (me thinks....)
Also, I bought some Bennic Polypropylene Caps - 2.2uF 5% - for input caps - I figured any poly cap should sound better than the stock electrolitic...and I paid $1.15 each at Madisound. I was going to buy Solen Poly Fastcaps for just ubnder $2, , but didn't think I would hear a difference...
Also, I bought some Bennic Polypropylene Caps - 2.2uF 5% - for input caps - I figured any poly cap should sound better than the stock electrolitic...and I paid $1.15 each at Madisound. I was going to buy Solen Poly Fastcaps for just ubnder $2, , but didn't think I would hear a difference...
Glad to hear your findings on the digital input. I do think the RCA in sound much better. But even the digital in is better than the moto player. Quite agree.
As far as not having the detail of the smaller T-AMPs, agree also. But even that analog signal from the RCAs is running thru a lot more electronics in the 501 than in our little T-Amps. Just think of the volume control. Probably a DCA or VCA of dubious quality. And who knows what else the signal is running thru?
That's one of the great things about pro gear, at least you get a flow chart! A service manual for this Moto-beast would be darn handy.
As far as not having the detail of the smaller T-AMPs, agree also. But even that analog signal from the RCAs is running thru a lot more electronics in the 501 than in our little T-Amps. Just think of the volume control. Probably a DCA or VCA of dubious quality. And who knows what else the signal is running thru?
That's one of the great things about pro gear, at least you get a flow chart! A service manual for this Moto-beast would be darn handy.
I beleive the CS4391 DAC's also do the digital volume control. I might be wrong, but I think all sound is routed through the multichannel processor, even if your just using stereo mode.
Would be nice to find out.
So you think that there is an ADC on every input? Then everything passes thru the DSP? Makes sense. That would make all the "effects" possible.
Ripping all that out and going directly to the power stage should really make a difference to the sound.
When someone gets it done, please report your results.
So you think that there is an ADC on every input? Then everything passes thru the DSP? Makes sense. That would make all the "effects" possible.
Ripping all that out and going directly to the power stage should really make a difference to the sound.
When someone gets it done, please report your results.
Well, I did the reverse of the above, I ripped the amp out and have been playing with it for the past few days.
I hooked it up to my mains using the exact same input caps I'm using on an AMP3. With the AMP3 on one speaker and the moto board the other playing at the same volume I could not tell a single bit of difference. To me it sounds just as good but with tons more power.
I tend to be less critical than most people, so you won't hear any kind of in-depth audiophile description of the sound from me. I like it, nuff said.😀
I have had moto #2 on since I got home using the FM tuner with the little FM wire that came with the unit. It is a nice tuner, it is very clear. I will have to try the $20 FM antenna that I have hooked up to the Onkyo receiver in the family room. That may add some depth, I will find out tomorrow.
I agree the moto gets "warm", but it's a "nice" warm not too bad.
I really like the moto and I can't wait to try to install the input caps. It has a lot of potential.
I agree the moto gets "warm", but it's a "nice" warm not too bad.
I really like the moto and I can't wait to try to install the input caps. It has a lot of potential.
theAnonymous1, I know you don't get into the in-depth description of the sound, but,... I would really like to know if the input caps brought out more midrange detail in the moto. It sounds like it did, if it sounds like your Amp3, "To me it sounds just as good but with tons more power." S o my question is, did the caps improve the sound of the moto?
Thanks!
Thanks!
Yes, there was an obvious and expected change in the sound.
I'll just say it was a change for the better and leave the details for you to describe once you replace your caps.😉
The caps I used are a little oversized at 4.7uf, but the way the unit powers up there is zero turn on thump.
I'll just say it was a change for the better and leave the details for you to describe once you replace your caps.😉
The caps I used are a little oversized at 4.7uf, but the way the unit powers up there is zero turn on thump.
Yes, its all I have at the moment. I'm having some 1kw switching supplies built, but it could be quite some time before I actually get them.