Quantcast

Page 13 of 15 FirstFirst ... 39101112131415 LastLast
Results 181 to 195 of 216

Thread: Take your Genesis audio to the next level - The Mega Amp 2.0 is here!

  1. #181
    Raging in the Streets Blades's Avatar
    Join Date
    Dec 2006
    Posts
    3,295
    Rep Power
    82

    Default

    Quote Originally Posted by Ace View Post
    This isn't quite right because while the Sega CD Model 1's RCA outputs will have unfiltered CD audio, the internal audio of the Genesis Model 1 has 1st-order low-pass filtered audio that includes the Sega CD audio, so you get a mix of both. The Genesis' internal audio is likely more predominant due to its high volume compared to the Sega CD RCA outs, and I expect it to drown out the unfiltered CD audio from the Sega CD's RCA outs.
    This doesn't sound right. The internal audio of the Genesis 1 does not include the CD audio if the mixing cable is connected.

  2. #182
    Road Rasher ironnick23's Avatar
    Join Date
    Nov 2011
    Posts
    337
    Rep Power
    11

    Default

    Thatís my thought as well. Connecting the mixing cable directly to a tv or receiver only plays music generated by the ym2612 or the Ricoh. When cd audio plays I donít hear anything out the mixing cable, but I do hear a buzz if I turn the volume up high. I considered maybe this is where the ferrite bead might play a role.

    I havenít tried pulling the rca cables from the scd but if the cd audio does goes through the headphone out, that would not seem to be the ideal way to hear music out of the console. There is something going on thatís funky in the midrange on the scd

  3. #183
    Nameless One BRNexus7's Avatar
    Join Date
    Oct 2014
    Posts
    81
    Rep Power
    6

    Default

    You should be hearing Sega CD audio through the Genesis Headphone out if you unhook the the mixing cable. Something must be wrong with your Genesis if you are not hearing Sega CD music out the headphone jack with mixing cable unplugged from Sega CD.

  4. #184
    Hedgehog-in-Training Hedgehog-in-TrainingSports Talker zeruel85's Avatar
    Join Date
    May 2016
    Posts
    33
    Rep Power
    0

    Default

    Hey guys.

    Just want to let you know that I have a new small batch of Mega Amp Pro ready to be shipped (assembled or un-assembled PCBs).

    I have a lot of back orders by people who have contacted me in the last months, so I will proceed in order and recontact everyone here in PM.
    Since the request is high and the batch is short, I will give everyone around 48 hours to reply to me and pay, otherwise I skip the order and proceed with the newer contacts.

    If the batch is too short, I'll go for another batch in the future, so don't worry about that.

    Thanks. Be patient and I'll contact everyone in the next few hours.

    People who have manifested interest:
    jlosacco - 1x SOLD - SHIPPED
    monitor - CONTACTED
    DrBackhands - CONTACTED
    Aras - CONTACTED
    Tianfeng - CONTACTED
    funky327 - CONTACTED
    beigemore - CONTACTED
    skipkfc - 1x SOLD - SHIPPED
    dark47 - CONTACTED
    compil3r - CONTACTED
    retroqc - CONTACTED
    Last edited by zeruel85; 08-20-2018 at 05:31 AM.

  5. #185
    Hedgehog-in-Training Hedgehog-in-TrainingSports Talker zeruel85's Avatar
    Join Date
    May 2016
    Posts
    33
    Rep Power
    0

    Default

    @funky327:

    if you do not empty your inbox, I cannot reply to your PM.
    If you want, you can also contact me via email:
    mod.luca [at] gmail [dot] com

  6. #186

    Default

    Hello everyone. First off, this is an awesome project! I've been planning on finally buying a Genesis one of these days, and I will absolutely mod the sound for it. I am an audiophile and music lover before a gamer, so sound quality is very important to me. I'm also an engineer, so I enjoy modding equipment to see what kinds of differences I can get. That said, I have a couple of questions about the available boards:

    Are there currently any boards that support all functions (including mono, even though I'll probably never use it) without problems?

    In addition to this, do any of these boards use standard-size capacitors as opposed to small surface mount ones? I have tons of audio-grade capacitors lying around my workbench, and since many of the caps on these boards appear to be directly in the audio signal path, I'd prefer the ability to mess around with different capacitors. I can solder through-hole capacitors on small surface mount pads, but that's a pain I'd prefer to avoid. Even if they won't make an audible difference, it's also money I can save, as I probably already own just about all of the capacitors necessary.

    I'm probably going to start with a model 2 with a YM3438, and later get a model 1 with a YM2612. I know that soundtracks composed with the YM2612's crossover distortion in mind sound better with it, but I have a feeling that I'm going to prefer the cleaner sound of the YM3438 with most games, which is why I plan to start with it. That said, since the model 2 doesn't have a headphone output, I could care less about having the power to drive headphones. I own dedicated headphone amplifiers powerful enough to destroy most headphones in a matter of seconds anyways. From what I've read, I'm starting to think that the older 1.2 is better for a model 2, as using a headphone amplifier as a line-amplifier typically results in a higher noise floor as well as distortion, at least partially due to the expected impedance being wildly different (line input impedance is quite high, while headphone input impedance is quite low).

    As for the model 1, I love the idea of having a headphone amplifier on-board for the headphone jack, but I would only want that going to the headphone out jack (I know that the output jack lacks a stereo output; I'll probably just add some standard RCA jacks).


    Then again, I admit that my experience at this level is limited, and I wonder if there are also limitations with power available. I also haven't found much info/measurements of a TDA1308 being used as a line amp instead of a headphone amp.

    I completely acknowledge that I'm getting into detail that is quite unnecessary for a vintage game console as opposed to actual audio equipment, but I enjoy experimenting and learning about this stuff.

    Thanks in advance, and again, this project is awesome!

  7. #187
    Hedgehog-in-Training Hedgehog-in-Training
    Join Date
    Sep 2018
    Posts
    1
    Rep Power
    0

    Default

    Are these still in production and available to buy?

  8. #188
    The legendary gargoyle Road Rasher Firebrandx's Avatar
    Join Date
    Oct 2010
    Location
    Texas
    Age
    45
    Posts
    347
    Rep Power
    18

    Default

    Question for Ace concerning the mixing schematic for model 1 discrete 2612 Genesis/MD consoles:

    I've stripped down the diagram shown on your OP to just the mixing section and removed the pull-downs based on the console already having them (as per your notes):



    We can see that you're obviously using polarized caps, and I can understand the direction of flow from the YM channels , but the reverse polarity for the other channels is something I don't understand. I tried looking at the triple bypass schematic, but Rene decided to use non-polar caps, so I got no help from that. Additionally, I noticed his mixing circuitry is slightly different... Edit: Just checked his github schematic and the resistors now match yours, so never mind about that.

    Main thing I'm curious about are all the polarities for the 1uf caps. Thanks for your input and clarification on this!

    -FBX
    Last edited by Firebrandx; 09-18-2018 at 01:14 PM.

  9. #189
    The legendary gargoyle Road Rasher Firebrandx's Avatar
    Join Date
    Oct 2010
    Location
    Texas
    Age
    45
    Posts
    347
    Rep Power
    18

    Default

    Okay I'm an idiot. I just re-mapped the audio schematic of my M1 VA3 and saw that the cap polarity is exactly the same as in the Mega Amp 2.0 schematic. So the process of installing a Mega Amp is simply removing those caps and tapping into the pads for them. I got it now. Thanks anyway.

  10. #190
    OPN2 in DNA Hedgehog-in-TrainingRoad Rasher Peeteris's Avatar
    Join Date
    Aug 2016
    Posts
    340
    Rep Power
    14

    Default

    Hey, where can I buy one?

  11. #191
    OPN2 in DNA Hedgehog-in-TrainingRoad Rasher Peeteris's Avatar
    Join Date
    Aug 2016
    Posts
    340
    Rep Power
    14

    Default

    Hello there.
    I installed the MegaAmp, unfiltered.
    It's all great and fun, but is there a cure to hissing and digital data transfer sounds? Thought that MegaAmp would reduce background noise, but I guess not, as it's louder now. 😀
    Any thoughts?

  12. #192
    Hedgehog-in-Training Hedgehog-in-TrainingNameless One
    Join Date
    Feb 2019
    Posts
    76
    Rep Power
    2

    Default

    I've never had those issues with a Mega Amp. Are you using shielded cables from your AV out to your TV? Are your lines touching anything they shouldn't in your Genesis? Are any lines close to the video or power regulator? Have you replaced the capacitors and power regulator in the Genesis? Those are some things I can think of, but there are a lot of places noise can be introduced.

  13. #193
    OPN2 in DNA Hedgehog-in-TrainingRoad Rasher Peeteris's Avatar
    Join Date
    Aug 2016
    Posts
    340
    Rep Power
    14

    Default

    Cables probably aren't shielded. Lines doesn't touch anything they shouldn't, as far as I see. Yes, there's one line close to both - I connected Audio Left channel to mono input, because many Chinese AV cables use mono audio as a left channel in their cables. The wire goes from Audio L in on the board straight to Mono in on the board.
    But there was this noise before I did this anyways. Maybe it was a bit quieter, who knows.
    Also, can Sega CD pads affect this?

    Because some time ago I tried other MegaAmp board, but didn't change anything here (shown in the picture) and didn't connect TR1&TR2 and noise was very low at that moment.
    Now I have done everything as shown in the first page here.

    Also, noise is not consistent, it changes with what is shown on the TV, so I can say that it's not some random noise, it's related to video signal.
    Any ideas?

  14. #194
    Hedgehog-in-Training Hedgehog-in-TrainingNameless One
    Join Date
    Feb 2019
    Posts
    76
    Rep Power
    2

    Default

    Before suggesting anything else, have you tried using properly shielded (official) Genesis cables? What you describe when noise is heightened by what's on screen are interference from non-shielded lines in the AV cable, and the Chinese cables suck especially with that mono as left line issue. If the noise is louder on bright (white) screens, like the SEGA screen on Sonic 1 or 2, that seems for sure a cabling issue. If you can't find real cables, wire up a standard 3.5mm Jack to your Genesis AV connector (or Mega Amp board). I'm at work so I can't reference a pinout, but just do a search to find the proper left channel and right channel. You can then just use the cheap cable for the video, while using a 3.5mm to RCA cable (like the kind you use to connect a cell phone Jack to AV equipment) for the audio.

    If after you do that and still have noise, then mark that off the list and continue to troubleshoot.

  15. #195
    OPN2 in DNA Hedgehog-in-TrainingRoad Rasher Peeteris's Avatar
    Join Date
    Aug 2016
    Posts
    340
    Rep Power
    14

    Default

    I connected 3,5 jack for test purposes directly to the Mega Amp Audio out and ground from a nearby capacitor. Noise is still there and louder (but probably because the whole volume is higher). Although, I should probably try this out without AV cable connected, because there might be interference thorough the circuit, when it's attached. I guess.
    There's always a noise and it changes even if some coloured plain text changes on black background. This is also the case with my Model 1 Mega Drive (using AV/RGB cables), but I don't mind that noise, because I use front 3,5mm audio jack anyways, where audio is almost spotless.
    But with this Genesis model 2, AV port is the only way to hear audio, and if even directly from the Amp sound is not clear, then this becomes a problem.
    That noise is not noticeable most of the time, because tracks are loud and diverse, but when there's plain silence or mellow/quiet tunes playing (like the first minute of Sa'eed cover by Savaged Regime), then that noise is really obvious. I can record that part, if it'll help understand the situation better.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •