motorola dcp501

I am also interested in how the 501 Amp section alone sounds compared to the Amp 6 or Charlize. That will be my first test.

I do not have the Amp 6, but I have the Amp 5 (not yet complete), and a TA2020 setup (not Charlize or Amp6), as well as a few gainclones, and a UCD180.

Have not yet did any critical listening on the 501 compared to those yet.
 
I have not opened mine yet, but my best guess would be that the signal flow is close to the diagram below. Simplified and only one channel, but probably pretty close to what is going on.
 

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theAnonymous1 said:
Well, after almost 8 hours of straight labor I have done a complete makeover to one of my moto's.

I started out by changing the over-current trip limit to allow for >4 ohm loads, then I replaced the 2.2uf electrolytic input caps with 3.3uf Jantzen MKP's.

Next I added another 10,000uf per rail to the supply. I took 2 caps from another moto supply board so they all match. I also changed out the 5v and 10v supply caps with Panasonic FC's and added some bypass caps to empty spots on the board.

The last and most difficult mod I did was replace the spring output terminals with binding posts. This took nearly 3 hours and 2 trips to the hardware store, not to mention extremely sore fingers. It wasn't fun at all.

Oh, I forgot I replaced the power cable with an IEC jack. Makes the unit look pro.😀

Here's a pic of the amp board with new input caps.....

http://i2.tinypic.com/2643q7s.jpg

Power supply board.....

http://i4.tinypic.com/2643r00.jpg

And lastly the back of the unit with binding posts and IEC jack.....

http://i2.tinypic.com/2643spi.jpg

I don't plan on doing this again any time soon; royal PITA.


Perhaps after all that work, you could post a drawing of the internal wiring pinouts (if you know them)? Some of us might just be inclined to remove everything but the power supply and the power amp board, and rewire it to run as 5ch power amp if we know where to solder what!
 
Perhaps after all that work, you could post a drawing of the internal wiring pinouts (if you know them)? Some of us might just be inclined to remove everything but the power supply and the power amp board, and rewire it to run as 5ch power amp if we know where to solder what!

Sure, but you'll have to be a bit more specific. Theres ton's of internal wiring, what exactly do you want to know the layout of; i.e power supply, amp board inputs etc.?

I you remove everything but the amp and supply you will have a huge empty box; the "other stuff" takes up most of the room. You would be much better off re-housing just the supply and amp.

I would also like to mention, that after all that hard work I'm putting my modded unit up for sale. I got carried away with the project and pretty much just did it for the..... ermm, adventure; I guess you could say.

As nice as the modds turned out and as nice as it sounds; I have no use for it as a complete unit. I'm not going to take it apart after all the time and effort I put into it, and I really don't want it sitting in my closet.

If anyone is interested all I'm asking for is my original investment + parts and shipping, no charge for my blood, sweat, tears, and time. I'll even throw in an extra remote.
😉
 
As good as it sounds, it did not replace your 5 channel Amp6 you currently have? Still prefer the amp 6 setup?

I have always said that a lot of what is expressed here is purely subjective, but would still be interested in your opinion on how it sounds compared to your Amp6.

I have more DIY amps and speakers than I have rooms in my house. My understanding wife is about to divorce me, my lawn hasn't been mowed in weeks, and my two boys don't recognise me anymore, but yet find this hobby extremely addicting (is there a DIY Anonymous yet?)...but my plan always was build everything i can get my hands on and keep the best sounding four, five or six amps and speakers. So I am alwys interested in other opinions.

"My name is John and I have a prblem with DIY Audio Equipment..."

I am streching this a bit, but would not be surprised about a few of us here......
 
As good as it sounds, it did not replace your 5 channel Amp6 you currently have? Still prefer the amp 6 setup?

It really has nothing to do with how it sounds. It's as pleasant sounding to me as the three AMP1-B's I have and the few AMP3's I've built(all given as gifts).

My 6-channel AMP1-B setup is in the middle of being completely redone. It will now be two stereo modules; each bridged to make a single 2-channel amp that will be put in my bedroom. The other module will be put in a drawer for now.

The amp boards from the other two motos I have will replace the 6-channel AMP1-B rig. I'm going to make two separate 4-channel power amps; leaving the center channel from each board unused.

One of the amps will do bi-amping of mids and highs, and the other one will power 4 15's, 2 per side.

All I will say about the moto's sound is it's very similar to the AMP1-B's and AMP3's I've built, with a MUCH lower noise floor than the AMP1-B's.
 
theAnonymous1 said:


Sure, but you'll have to be a bit more specific. Theres ton's of internal wiring, what exactly do you want to know the layout of; i.e power supply, amp board inputs etc.?

😉


Specifically I was thinking of the input/output wiring on the amp board (power leads to it too would be nice touch).
Good on ya sellin' off your baby, I tend to hoard my projects, really should clear a few out 🙂
 
Moto #1 continues to break in nicely. Moto #3 appears to be very musical right out of the box, I need to unplug moto #1 and play moto #3 more.

I am eagerly awaiting the arrival of theAnonymous1's modified moto. It sure looks great! I was lucky to be the who got it. I can't wait get and to listen to it!

Thanks again theAnonymous1.
 
Keep the info coming.

I just purchased one. Had looked at it before (quite awhile ago when they were trying to get rid of them at $150-$200 I think), but was too much $$. Now that its <100 shipped, can hardly go wrong.

I just recently finished (meaning sound comes out, not that its completely done) my Amp6/Kookaburra/Cheap DAC combo http://tinyurl.com/rxkeq , and it sounds very nice to me (although I have not much to compare with except standard $150 receivers that sound terrible to me).

It took me a couple months to finish these kits (lack of time), and would take another couple (at least) to make an input selector/lcd display/cabinet/remote/etc. So I hope the dcp501 will sound as good as the Amp6, so I can get back to all my 'regularly scheduled' projects.

If all goes well, I can sell my parts/kits and actually have less money into this audio stuff than before.
 
curtvm said:
So I hope the dcp501 will sound as good as the Amp6

It won't, unless you modifiy it (maybe). Having all those in and outs, tone controls , etc. is nice. But there s no contest between the SQ of the AMP6 and dcp501 in my system/room.

I tried to use the surround function, but it realy kills the front channels. Seems that the DSP is the bad part of this unit.
 
panomaniac said:


It won't, unless you modifiy it (maybe).

Oh well, then it will be used while I finish my amp6 system. Maybe my ears won't be good enough to tell the difference, we'll see.

It's quite amazing that the amp6 sounds as good as it does (for such a little thing+cheap+no heat). I'm glad I headed in the class D direction- I didn't know what amp kit to get initially, but decided on amp6 because it was cheap and no major heatsinking involved. It worked out good with my fe167 speakers- puts out more than they can handle.
 
Panomaniac,

Have you or are you planning on bypassing the DSP totally and running straight through the DCP-501 Amps? Like you said the thing that sours the performance of the DCP is the DSP, and all the other "stuff"...

I would be interested in seeing the comparision vs Amp6 straight up. I would think it would be a bit more cleaner and comparable to the Amp6. I plan on checking in on it as soon as I am able to dedicate the time (work's a bear now)

All the Tripaths chipsets (TA2020, TA2022, TA2024, TA3020), based on similar mods (input caps, etc), sound very similar to me, and generally just vary on power output and minor details (just my opinion folks).
 
john65b said:
Have you or are you planning on bypassing the DSP totally and running straight through the DCP-501 Amps?

I do plan to, soon. It shoudn't be too hard, if all the stuff goes in a new box.
Perhaps it would be possible to reroute the preamp out RCA connectors to go straight to the power amp and use the case as is.

Worth a look.
 
theAnonymous1's Modified Moto

Thanks again theAnonymous1's!!! It's awesume.

Let me start out by saying that you should try the OPTICAL CABLE with the moto!

panomaniac, No wide effect at all using the Optical, like with the coax.

theAnonymous1's modified moto sounds great with the RCA's also!!! In fact I have two DVD players hooked up to it. The DVD player that I had hooked up to the SI has the RCA's going to the moto. The other one I grabbed from my main DVD/widescreen TV system hooked up for surround sound in the family room with the Onkyo. It has an optical out. It may not be going back down. Very cool to switch between the two with the moto remote.

Now to the review of theAnonymous1's moto. I'm hearing details in the music that I didn't hear before with the SI. And this is music that I know what to listen for. theAnonymous1's moto has great clarity, and a calmness about the presentation. There is plenty of bass, a wide soundstage, and tons more power and air than the SI. A huge amount of fade and decay in the details are also evident! You hear the little details at the ends of notes. Also much more detail in the midrange than the stock moto. The last detail I will mention for now is that the noise floor is VERY low, theAnonymous1 also mentioned it. It's quiet. I need to listen to it much more.

This receiver is a work of art as far as I'm concerned! Great job theAnonymous1!

I will give more details after I listen to it more. I've only been able to listen to it for a few hours.
 
Thanks for the kind comments; I'm glad you like it.

I was very happy with how it turned out and it makes me feel good to know it will be used and enjoyed instead of sitting around my house until I could find a use for it.

Here are some pics of my newly redone AMP1-B that I'm using until I can get all the parts to rehouse the boards from my other two moto's.

The power supply is +-28v @ 12A with 44,000uf per rail, wayyyyy overkill, but it has some superbly powerful bass.

http://i18.photobucket.com/albums/b118/theAnonymous1/amp1b_front.jpg
http://i18.photobucket.com/albums/b118/theAnonymous1/amp1b_back.jpg
http://i18.photobucket.com/albums/b118/theAnonymous1/amp1b_inside.jpg
http://i18.photobucket.com/albums/b118/theAnonymous1/amp1b_inside2.jpg
 
Hey John, I was also going to build that kit but I wanted a DAC that didn't need a preamp.

After doing tons of searching on cost vs. quality I ended up buying 3 Entech Number Cruncher 203.2 DAC's. I bought them off ebay and got all three shipped to my door for around $110.

I'm in the middle of building new power supplies and rehousing them in one chassis with remote volume control. I also did the CS8412 "filter mod" that I found on this forum. I have no clue if it made a difference, but it was easy to do and only took 2 caps and a resistor.

I'm overall pleased with how the Entech sounds and I'm glad I didn't have to assemble 3 boards, not to mention I could't even find any kits for as cheap.