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Modding the Pyle PAMP1000 (and some Soldering Lessons)

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  • Modding the Pyle PAMP1000 (and some Soldering Lessons)

    This is basically an extension of the AudioSource AMP-100 mods since the PAMP1000 is a pretty close (but not exact) copy of the AMP-100. I'm fairly sure the Dayton APA-100 is similar again, but I won't guarantee that any of my mods will work on the Dayton since I don't have one. I'll be editing these posts as I go along and also posting some soldering videos to ease anyone's concern over making these modifications.

    Here's the link to the PAMP1000 at Menards and at Amazon.
    http://www.menards.com/main/electric.../p-1706836.htm
    http://www.amazon.com/Pyle-PAMP1000-.../dp/B002UL0XH2

    Here's the Mouser cart that contains all the modification parts for this project (total current price is $40.21, only about $3 more than the AMP-100 because of some extra parts you need):
    https://www.mouser.com/ProjectManage...sID=8570532559

    First Impressions:

    OK – my first impression of this thing coming out of the box is that it’s a PYLE of poopy, but there are a few nice features. There’s a detachable AC cord, which is nice. Also, the initial sound of the amplifier is what I would call above-average, especially for its price. I only paid $70 for these at Menard’s when they were on closeout. They can be had all over the internet for $80 or $90. I think the initial sound actually exceeds the initial (non-reworked) audio quality of the AudioSource AMP-100. This has to do with the fact that the Pyle chose to use better quality audio op-amps than the AudioSource did. Pyle chose TL072 op-amps for the I/O board and a uPC4570 for the volume control buffer. AudioSource used slow and cheap 4558’s all around.

    Unfortunately, the build quality is horrid. One of my two units had the left and right channels swapped on the “A” speaker output (the “B” speaker output was correct). The main board was not properly inserted into its mounting slot on the front of the unit, and this was causing it to badly warp. The two main power resistors (which dissipate power and reduce the voltage level for the op-amps), were soldered directly onto the board. These resistors really need to be elevated off the board in order to dissipate heat. Finally, the rear I/O board is twisted because the manufacturer neglected to use the correct footprint for the RCA connector they chose. I’ve got fixes for all of these issues, but it’s just indicative of the very poor build quality of these units.

    Oh and the screws and sheet metal on this unit are world-class bad. The manufacturer had even used a wood-screw in one location where they had stripped out the sheet metal. You need to find a screwdriver that fits the heads exactly, or you can expect some stripped heads. I find that a relatively flat (rather than pointed) phillips head worked best.

    The strangest part - all of these build quality issues were on ONE of my two units. The second unit had virtually none of these issues.

    Once the unit gets modified, it keeps up with my modified AMP-100 (sounds just like it) and my NAD C315BEE amplifier. It’s really quite nice, and well worth the time investment. The difference between the non-modified Pyle and the modified Pyle is not extreme (like it was for the AudioSource), but it really opens up the clarity of the treble and mid-range, and it it tightens up the bass quite a bit. I followed the basic footprint for modifications that I defined on the AMP-100, but there are just a few more components to replace and a few different selections because of the different component sizes on the Pyle.

    On to the modifications (and polishing up the diamond in that goat's rear end):
    Last edited by tyger23; 05-03-2015, 10:57 AM.

  • marstedt
    replied
    Looking at picking up a few of the AMP-100. Any comments on alternative opamps for the out-of-stock lm4562? I think there's still some stock on the NJM4562.

    Update, here's the response:
    http://techtalk.parts-express.com/fo...91#post1273091

    Last edited by marstedt; 03-14-2016, 01:14 PM.

    Leave a comment:


  • silverD
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    Thanks tyger. I'll pickup the caps from Digi-Key.
    Nate

    Leave a comment:


  • tyger23
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    I'd probably go with these:

    http://www.mouser.com/Search/m_Produ...vesCT0sEX4c%3d

    The FG's are in stock at digikey if you want.

    Leave a comment:


  • silverD
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    Hi tyger,
    I just picked up 2 PAMP1000's from Menards and plan on doing the mods. I was about to place the parts order from mouser when I noticed that the UFG1E470MEM are on backorder for some time. What do you recommend as a replacement?
    Thanks,
    Nate

    Leave a comment:


  • tyger23
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    Originally posted by Pete Basel View Post
    I see that you change the main PSU caps to an excellent quality, low ESR, 105 deg C type,
    do you hear an audible difference as a result of the better caps or is it just a precaution?
    Do you see a change in measurements?
    What brand were the original caps?
    I'm looking at the very cheap Sherwood 4109 and the caps are all from Samyoung, lol!
    The original PSU caps had no name brand, and no marking as to their value. They measured at about 3300uF, which is half of the 6800uF, 50v value stated on the silkscreen of the board (and the value used in the AudioSource original design). Also, the original caps, despite their relatively large size, were light as a feather.

    Changing those PSU caps probably has no effect at very low volumes, as they were still doing an adequate job of smoothing out the power supply under light loads. However, changing the caps to the better quality allows for the amp to perform well under loads that the amp is actually rated for, and it very much improved the bass punch. Please note, however, that I changed ALL the caps on the board. After measuring the PSU caps, I didn't trust any of them.

    When re-capping an amp, I generally go for an all Nichicon solution. For the signal path, I try to use Nichicon FG or KZ caps. I prefer KZ caps when I can get them to fit. I've used Elna Silmic II's in the past, but they're a bit shrill to me. I personally prefer the "smoothness" of the Nichicon. For the power supply and bypass caps, I like to stick with Nichicon KA or KW. KA for the 105 degree stuff and KW for the less heat or load sensitive stuff. I've also used Panasonic TSHC for power supply bulk caps with good success, but I saw that they are being discontinued. That's why I decided to try the Vishay stuff for this project. I like to stay at 105 degree caps for the power supply regardless of the proximity to heat because the 105 degree caps are rated for a much longer lifespan at 85 degrees than a typical 85 degree rated cap. Enjoy!

    Leave a comment:


  • Pete Basel
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    I see that you change the main PSU caps to an excellent quality, low ESR, 105 deg C type,
    do you hear an audible difference as a result of the better caps or is it just a precaution?
    Do you see a change in measurements?
    What brand were the original caps?
    I'm looking at the very cheap Sherwood 4109 and the caps are all from Samyoung, lol!

    Leave a comment:


  • Psycoacoustics
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    Originally posted by tyger23 View Post
    I tried running these in bridged mode, and there's a good bit of hum coming through the speakers when that's enabled (and a source is connected). This seems to echo the experience that Psychoacoustics had with trying to bridge the AMP-100's. I think the issue is the obfuscated way that they route the feedback from the right channel to the left amplifier, but I'll have to experiment to be sure. If anyone's interested, I'll try and figure this out.

    However, they sound great in normal stereo mode, and they've got a lot more power on-tap than they seem rated for.
    I'm not happy your getting a hum but,,,,,, I am happy it wasn't just ME!

    If you can figure it out it may talk me into trying a couple. Later, Mark

    Leave a comment:


  • tyger23
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    I tried running these in bridged mode, and there's a good bit of hum coming through the speakers when that's enabled (and a source is connected). This seems to echo the experience that Psychoacoustics had with trying to bridge the AMP-100's. I think the issue is the obfuscated way that they route the feedback from the right channel to the left amplifier, but I'll have to experiment to be sure. If anyone's interested, I'll try and figure this out.

    However, they sound great in normal stereo mode, and they've got a lot more power on-tap than they seem rated for.

    Leave a comment:


  • tyger23
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    Here's a video showing how to solder op-amps, capacitors, and IC's. Enjoy:



    In case anyone was wondering - the soldering equipment you see in this video is:

    1. Metcal SP-200 solder station (discontinued)
    http://www.testequipmentdepot.com/me...tems/sp200.htm

    2. Metcal SSC-626A soldering tip.
    http://www.techni-tool.com/551TI134

    3. Edsyn Deluxe Soldapullt, Heavy Duty, High Vacuum
    http://www.techni-tool.com/330ED082

    4. Xcelite Diagonal Cutters
    http://www.techni-tool.com/294PL158

    5. Stainless steel precision tweezers:
    http://www.techni-tool.com/758TW450
    Last edited by tyger23; 05-03-2015, 12:42 PM.

    Leave a comment:


  • tyger23
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    This video shows how to replace the relay. You'll note that this is similar to the process I used for the RCA connector.

    Leave a comment:


  • tyger23
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    Here's one showing how to remove a resistor. This also works for some ceramic disc capacitors.

    Leave a comment:


  • tyger23
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    This video shows a technique for removing IC's like the opamps. This also works for the pots. There's also a small bit on removing a cap.

    Leave a comment:


  • tyger23
    replied
    Re: Modding the Pyle PAMP1000 (and some Soldering Lessons)

    The videos are uploading and it's taking a while. In the mean time, here's the schematics I re-created and edited to indicate which components to change.

    https://drive.google.com/file/d/0B_P...ew?usp=sharing

    Here's a video that shows how to remove the RCA connector from the rear I/O board. The technique can apply to most connectors and large thru-hole parts like the main power supply caps.

    Last edited by tyger23; 05-03-2015, 10:49 AM.

    Leave a comment:


  • tyger23
    replied
    Modding the Pyle PAMP1000 (and some Soldering Lessons)

    Main Board Reworks:
    1. Replace the snubber capacitors around the DC converter circuit.
      • Change C9 and C10 to quality film caps (0.1uF, 250V). (MMK10104K250A01L4BULK)
      • Change C3 and C4 to quality film caps (0.1uF, 100V). (MMK7.5104K100K00L4BULK)
    2. Replace the power supply capacitors with quality versions that actually measure what they advertise.
      • Replace C1 and C2 with snap-in capacitors (6800uF, 50v, 25x40mm). (MAL225631682E3)
      • Change C5 and C6 to Nichicon KA series (470uF, 25V). (UKA1E471MPD)
      • Change C7 and C8 to quality MLCC capacitors (0.1uF, X7R, 50V). (K104M15X7RF53H5)
      Click image for larger version

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    3. Remove the RF trap capacitors from the input section (C200 and C300). Do not replace.
    4. Change the pots out for better quality Bourns potentiometers.
      • Click image for larger version

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      • VR2 will change to a 100K linear taper pot. (PDB182-K220K-104B)
    5. Remove the series capacitors and short across them (C201 and C302). You can see the shorts in the picture of the bottom of the board above.
    6. Change the op amp and optimize the gain through this circuit:
      • IC5 changes to LM4562. (LM4562NA/NOPB)
      • Change R204 and R304 to 3.9K, 1%, 1/4W. (271-3.9K-RC)
      • Change R203 and R303 to 34L, 1%, 1/4W. (271-34K-RC)
      • Remove the low-pass filter capacitors C203 and C303.
    7. Optimize the gain and circuitry around the amplifiers:


    Here's what the top of the board looks like when you're done:
    Click image for larger version

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    Fix any Remaining Mess Ups (if applicable):
    1. If your left and right channels are swapped, the issue is likely at the speaker switching PCB. I had to swap my white and yellow wires. When I was done, it looked like this.
      Click image for larger version

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    Last edited by tyger23; 05-03-2015, 03:21 AM.

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