tkarner Posted February 12, 2010 Share Posted February 12, 2010 Is there an internal adjustment in the 7800 to adjust the audio output? The volume on mine seems too high. It's louder than my other consoles and it sounds distorted with some games. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted February 12, 2010 Share Posted February 12, 2010 No, there isn't, though I suppose you could change the resistor that the volume goes through to a different value to drop it. Probably just easier to just turn the volume on the TV down. Is your 7800 modded or anything? I don't recall ever having a problem with the volume on any of my 7800s. Mitch Quote Link to comment Share on other sites More sharing options...
tkarner Posted February 12, 2010 Author Share Posted February 12, 2010 I was hoping there was a pot in there somewhere. No, it's not modded. I was using another 7800 but the picture went bad on that one so I'm using this one now. I deal with the volume as you said, just turning down the TV volume. But that doesn't solve the distortion problem caused by the gain being too high in the first place. If changing the resistor isn't too much trouble I can do that. Can someone point me in the right direction with a diagram? Quote Link to comment Share on other sites More sharing options...
+Mitch Posted February 12, 2010 Share Posted February 12, 2010 How familiar are you with electronics? No offense intended but you need basic electronics and soldering skills if you want to try and fix it. Mitch Quote Link to comment Share on other sites More sharing options...
+save2600 Posted February 12, 2010 Share Posted February 12, 2010 I've noticed with certain games, things seem to be louder and more distorted. DK comes to mind. Maybe it's just certain games you play all the time? Quote Link to comment Share on other sites More sharing options...
kenfused Posted February 12, 2010 Share Posted February 12, 2010 I've noticed with certain games, things seem to be louder and more distorted. DK comes to mind. Maybe it's just certain games you play all the time? The intro music and sound effects in 7800 Donkey Kong may kill some canines and may cause deafness in mice :!: Quote Link to comment Share on other sites More sharing options...
Kjmann Posted February 13, 2010 Share Posted February 13, 2010 (edited) I've noticed with certain games, things seem to be louder and more distorted. DK comes to mind. Maybe it's just certain games you play all the time? The intro music and sound effects in 7800 Donkey Kong may kill some canines and may cause deafness in mice :!: I agree. The Nintendo Titles for the 7800 were some of the most Horrifying Music tracks and SFX I've ever heard. The 7800 Really needed a better Sound chip. The 2600 sound that it has was the one major let down of the system for me. Edited February 13, 2010 by kjmann Quote Link to comment Share on other sites More sharing options...
mimo Posted February 13, 2010 Share Posted February 13, 2010 Pokey is a pretty good sound chip as you know.Just a shame that it was so under used and not actually included built in to the 7800 Quote Link to comment Share on other sites More sharing options...
tkarner Posted February 15, 2010 Author Share Posted February 15, 2010 Now that you mention it, Donkey Kong is the worst offender. So it seems that maybe there isn't anything wrong with my console? (though I don't remember my previous 7800 sounding like that). Oh well, I guess I'll leave it alone then. Quote Link to comment Share on other sites More sharing options...
DracIsBack Posted February 15, 2010 Share Posted February 15, 2010 The 7800 Really needed a better Sound chip. The 2600 sound that it has was the one major let down of the system for me. The chip is definitely a let down for me too. Also the fact that programmers didn't do a great job with TIA sounds in many cases, limitations and all. Quote Link to comment Share on other sites More sharing options...
gdement Posted February 16, 2010 Share Posted February 16, 2010 Here's the audio portion of the motherboard schematic: Both TIA channels are tied together (AUD1 and AUD0 on the left side of the diagram) They go through an 18K ohm resistor at R6. The external audio from cartridges (POKEY) goes through a 6.8K ohm resistor at R5. If either of those sources is too loud, you could check those resistors with a multimeter. Unfortunately the resistors cover up the board markings, so it's not easy to tell where these resistors are located. The TIA resistor (R6) could be found by checking for continuity with TIA pins 12 and 13 (which are the sound output pins). Based on the last photo in this post Looks like R6 is immediately to the left of the red coil, and R5 is to the left of that. Quote Link to comment Share on other sites More sharing options...
desiv Posted January 21, 2013 Share Posted January 21, 2013 Reviving this thread for a question. I did a composite mod, which works well.. Audio is good, and in games like BallBlazer and Commando, I can hear POKEY sounds fine.. But I tried a few homebrews (Beef Drop comes to mind) and the pokey volume seems lower. Probably intentional as I think music should generally be softer than game sounds, but when I turn up the volume so I can hear the Beef Drop music, the game sounds are MUCH louder.. I was thinking maybe if I dropped the volume on the TIA sounds a bit, it might help... I can do some soldering (I did the composite mod), but my understanding of what I'm doing is not that great. What rating resistor would be likely to drop the TIA volume a bit? (Obviously, as "a bit" is relative, I'm not looking for super precise answers, just likely SWAGs) Also, I just got a new solder rework station for Christmas and every thing I see (such as this) seems to need soldering.. Thanx, desiv Quote Link to comment Share on other sites More sharing options...
kenfused Posted January 21, 2013 Share Posted January 21, 2013 The mod might be limiting pokey volume too much. in my 8bit domain board pokey was really faint (among its other issues). I lowered a resistor value which helped some but I really need to lower it some more. Beef drop does use TIA for some of the sound effects. It might be that ballblazer or commando doesn't. I think ballblazer only uses pokey for sound but not sure on commando. Quote Link to comment Share on other sites More sharing options...
kenfused Posted January 21, 2013 Share Posted January 21, 2013 Do you have to change the volume when switching betwwen pokey carts and other 7800 carts? Quote Link to comment Share on other sites More sharing options...
desiv Posted January 21, 2013 Share Posted January 21, 2013 Using a CC2, so not sure about cart changes... It's the 7800 mod that pops up for sale on e-bay. Now that I try it again, Commando is also similar. When I turn up the volume so I can hear the music, the game sounds are just a bit too loud for my tastes... BallBlazer is also similar, so I guess I didn't really notice it before, but I'm sure it's just related to my video mod. I noticed it because of Beef Drop because that awesome pepper sound is very different from the music.. I'm guessing I'm looking for a pretty small decrease in the TIA sounds here.. (I suppose I could look at boosting the Pokey sounds, but was thinking decreasing TIA would be easier..) desiv Quote Link to comment Share on other sites More sharing options...
+Mitch Posted January 22, 2013 Share Posted January 22, 2013 Most 7800 A/V mods have the audio portion wrong for Pokey games. I've posted about this a couple times in the past. I'll try to search for the posts when I have a few minutes. Mitch Quote Link to comment Share on other sites More sharing options...
7800 Emucoder Posted January 22, 2013 Share Posted January 22, 2013 In my composite mod, I clipped the top connections(towards the back of the console) of both R5 and R6 from the board, leaving the bottom posts still attached to the board (the ends facing the joystick ports), and soldered the clipped ends of the resistors together, and this constitutes my audio signal. This gives perfectly mixed audio between TIA and POKEY. 1 Quote Link to comment Share on other sites More sharing options...
desiv Posted January 22, 2013 Share Posted January 22, 2013 The mod I used had me remove C10 and wire up the pokey to there: http://www.vintagegamingandmore.com/wp-content/uploads/2010/06/IMG_0514.jpg The TIA audio came from the feed to the (now non-existant) RF modulator. I'm wondering about maybe a potentiometer or variable resistor maybe to drop the TIA??? No idea about ratings tho... Thanx, desiv Quote Link to comment Share on other sites More sharing options...
Dauber Posted January 23, 2013 Share Posted January 23, 2013 Yup, that's the exact same mod I did. I've been in touch with the guy who runs that site, and from what I gather, you and I are having unusual problems in this regard. He suggested trying a 20k pot (where do I get one???) and seeing if that helps. Wonder if some kind of preamp would help too....?? Quote Link to comment Share on other sites More sharing options...
desiv Posted January 23, 2013 Share Posted January 23, 2013 (edited) Yup, that's the exact same mod I did. I've been in touch with the guy who runs that site, and from what I gather, you and I are having unusual problems in this regard. Well, I doubt that, but.. He suggested trying a 20k pot (where do I get one???) and seeing if that helps. Wonder if some kind of preamp would help too....?? I'm guessing an electronics shop. I could go e-bay if I was sure. Something like this: eBay Auction -- Item Number: 380523434703 (Not endorsing that. I just searched for 20k pot on e-bay..) But I'd rather try something out to make sure it will work... Nice thing about a pot/VR is that, once I find the "proper" value, I could measure the resistance and people could just use a resistor in the future. But, as I don't have a pot/VR handy, I'm not sure I want to invest yet.. I have some resistors around, so I could just try a few and see what they do.. If the mod we chose has that issue, I'm not sure about going another mod route, as that means putting things back in and I'm not sure I saved everything I pulled out.. desiv Edited January 23, 2013 by desiv Quote Link to comment Share on other sites More sharing options...
+Mitch Posted January 23, 2013 Share Posted January 23, 2013 Here's my previous post on how to fix the unbalanced audio issue. http://www.atariage.com/forums/topic/185950-lhe-mod-problems/?do=findComment&comment=2343932 Mitch Quote Link to comment Share on other sites More sharing options...
Dauber Posted January 23, 2013 Share Posted January 23, 2013 Thanks, Mitch...now, I don't know much about electronics -- for example, I have no idea how to interpret a schematic, I actually need English instructions! -- so I need to ask seemingly ignorant questions... - One end of each of the blue resistors in your picture is connected to the bottom leg of the two resistors to the left of that tall red thingy. Which resister is which, and which way should they be facing? - Just to be clear, the now-free ends of the new resistors need to be soldered together, and then have a wire soldered to the united resistor legs??? Quote Link to comment Share on other sites More sharing options...
desiv Posted January 23, 2013 Share Posted January 23, 2013 (edited) which way should they be facing? Ah!! That one I know!! Doesn't matter with resistors.. They can face either way. Well, that's the extent of my electronic expertise.. Our mod is a bit different than the one mitch listed... Be interesting to see if the "fix" can be back ported.. Looking at the different pickup spots, I'm not sure.. desiv Edited January 23, 2013 by desiv Quote Link to comment Share on other sites More sharing options...
+Mitch Posted January 23, 2013 Share Posted January 23, 2013 Can you guys post some pics of the mod you have? Mitch Quote Link to comment Share on other sites More sharing options...
desiv Posted January 23, 2013 Share Posted January 23, 2013 http://www.vintagegamingandmore.com/installation-guide-7800/ This one. desiv Quote Link to comment Share on other sites More sharing options...
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