Troubleshooting AVR-2802 - Good 5.1 CH analog input/output receiver ? - Page 1
Forum section: electronics / repair

author: MathWizard
author_rank: Super Contributor
timestamp: January 11, 2024, 09:38:16 pm
content: I need a better 5.1 system for PC audio, like low latency online gaming. So I want to get some better speakers, and a receiver, a few hundred watts is more than enough. I don't want to hook anything else to it, besides my PC soundcard.I have a good AE-5 plus soundblaster soundcard, it already should do any and all digital processing, before outputting to 5.1ch RCA jacks, from a 32-bit DAC. So I would think an older receiver, without a pile of extra digital and video stuff, should be good for me.Most receiver's these days don't have 5.1CH analog inputs. And I don't want to add more latency, and software+soundcard should do everything anyways right ?So any recommendations for a receiver that sounded good, and maybe had a minimum of hard to find chips ? IDK, maybe the average receiver from the 90's/2000's, already had a lot of custom hard to find parts, and all their caps would be wearing out ??I'm mainly looking on ebay. I could get something new, but again most don't have 5.1CH inputs, and that would add another digital layer, before the speakers.Any recommendations ?

author: bdunham7
author_rank: Super Contributor
timestamp: January 11, 2024, 10:09:32 pm
content: I have a Marantz SR7008 about a decade old and it has full 7.1 analog inputs. I believe the lower models didn't have that, it was sort of "flagship model has every possible feature" sort of thing. It's not going to have the repairability and jellybean parts of a 1980 model, but I think that by the time 5.1 surround was a thing, the old-school designs were already fading fast. They go fairly cheap on eBay because they aren't up to date with current video and surround features. They've gone to marketing strategy of introducing a new model every year.

author: MathWizard
author_rank: Super Contributor
timestamp: January 11, 2024, 10:31:21 pm
content: I've seen the Marantz name a few times, IDK if all their stuff is good, but yeah I'll watch for them. I would find it fun to try repairing some of the older stuff, but I remember some of it would have to be matched to the other parts.I didn't know all this stuff was going so digital, most motherboards and soundcards still have 3.5mm outputs for 5.1CH, so I expected all the new receivers to have it still.

author: themadhippy
author_rank: Super Contributor
timestamp: January 11, 2024, 10:31:59 pm
content: Quotesurely then all you need is 6 power amps

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 10:25:22 am
content: Quote from: MathWizard on January 11, 2024, 09:38:16 pmI know for a fact that the Denon AVR-19xx series route their external surround inputs directly to the power amps. If you have any plans to be near Washington DC soon, I have an AVR-1906 that’s been sitting boxed in my friend’s basement for years, you could have it if you want. (But shipping it would cost more than it’s worth, so I’d buy one locally otherwise.) Models below the AVR-19xx series don’t have the analog external surround inputs, but I’d expect those inputs on higher series to work the same. Older models like the -1906 that have only analog video go for peanuts used, and now the same fate is befalling newer ones whose HDMI ports don’t support 4K, like the AVR-1910 I currently use. The video portion doesn’t matter since you won’t be using it.With that said I wouldn’t worry about latency with S/PDIF digital or with models that digitize all the inputs first (like the Sony STR-DB2000 I also have); it should be extremely small since these were made to keep in sync with a CRT TV, which has very little input latency. (It’s the dumb HDCP encryption in HDMI and co that adds latency. D/A conversion itself is fast enough that the speed of sound between speaker and ear is going to be a bigger delay.

author: Zoli
author_rank: Frequent Contributor
timestamp: January 13, 2024, 03:34:01 pm
content: Look in thrift stores(Salvation army, Value village, etc.); I've seen 5.1 AV-centres as low as 29.99 CAD.

author: wasedadoc
author_rank: Super Contributor
timestamp: January 13, 2024, 04:35:25 pm
content: Why is this in the repair section of the forum?

author: MathWizard
author_rank: Super Contributor
timestamp: January 13, 2024, 04:59:01 pm
content: I'm being cheap and in a rush, so I'm looking at a lot of old stuff that might have problems or will be untested anyways. The less custom digital stuff, the easier it should be to patch up too, if it breaks.Shipping from the states usually adds too much cost.There's a few with the 5.1ch RCA inputs, like a Denon 1804, or a 3806 (7.1ch). I think I saw a 190x too.I'm confused about some of this digital audio, and surround channels in general. I have DVD's, all bought before say 2012. I have no plans to get a blu-ray player. So I'm still assuming my soundcard and just a basic 5.1ch audio amp. should be able to do everything, with the analog from the soundcard.

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 05:18:16 pm
content: What is it you're trying to do, then? Play games or watch DVDs?Any home theater receiver is basically toast if anything digital fails, since the microcontrollers control all the signal routing (which is, aside from power amplification, arguably their biggest task).If your PC sound card has an optical or coaxial S/PDIF digital output, and your games can use this, then that's the easiest and best way to get sound to the receiver. (Optical has the added advantage of being galvanically isolated, so no ground loop problems.) The AV receiver will automatically configure for the data format sent.What do you need to know about digital audio and surround?

author: coppice
author_rank: Super Contributor
timestamp: January 13, 2024, 05:36:02 pm
content: Current AV receivers have some weird choices. Most only have stereo connexions for the analogue inputs, yet fill up the back panel with lots of RGB and composite analogue video inputs and outputs that I can't imagine many people using in 2024. An input is good, for hooking up that old VHS or laserdisc player you still have treasured media for, but who still needs an RGB analogue output?

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 05:58:25 pm
content: Quote from: coppice on January 13, 2024, 05:36:02 pmI don't know what you're talking about.Modern AV receivers are dominated by HDMI inputs. And some analog audio for sure. Usually some digital audio inputs too.As you depart from the entry level models, analog video inputs are added, then S-Video, and then higher still, maybe a component video input. Nobody (AFAIK) puts RGB inputs on them, that's really never been a thing in home cinema.

author: coppice
author_rank: Super Contributor
timestamp: January 13, 2024, 06:14:42 pm
content: Quote from: tooki on January 13, 2024, 05:58:25 pmMy Marantz NR-1711 seems typical of a modestly priced receiver. Its last year's model. It has 2 sets of RGB input phonos, labelled "DVD" and "media player", and one set of RGB output phonos labelled "monitor". Its has 3 composite video in phonos, and one composite video out phono.

author: MathWizard
author_rank: Super Contributor
timestamp: January 13, 2024, 07:25:08 pm
content: I don't have a TV, so it's just a 5.1ch system for my PC for games, and music/video's. And it has a DVDburner, but I really don't like those any more, they are super loud.I don't like headphones much, they get uncomfortable.For years's I've used RCA from a soundcard, into a really cheap pc gaming 5.1 ch system. Just getting better speakers, and just about any receiver, should be an improvement in sound.In games, even offline, like shooter's or racing games, I just want to minimize lag, from any extra digital audio processing. I read some article, and some setups, like optical, will add dozens or hundreds of ms of lag. Some people have issues like that with watching movies and streaming too.Here's something I don't get, in my new soundcard settings for Dolby audio for example. It says it will "encode" any stereo signal to Dolby, and then you have to output that digital signal to a digital receiver. And so then doesn't the receiver convert it to analog for the speaker outputs ?My soundblaster AE-5 soundcard has RCA analog outputs already, they just have to be amplified. So can't it do the Dolby mixing, convert it to analog, and nothing besides amplification is needed ??I don't want to spend a fortune, and I know there's used ones that will have problems over my head, or hardly worth fixing. I don;t want to troubleshoot one for a month either, so IDK what to do.

author: Zoli
author_rank: Frequent Contributor
timestamp: January 13, 2024, 11:09:00 pm
content: Quote from: MathWizard on January 13, 2024, 07:25:08 pmIf you want to minimize lag, all-analog is the way to go; not optical or coaxial. As a rule of thumb, look for receivers without HDMI; is a good chance to have an all-analog chain available. As side-note, during today's thrifting I've seen two receivers with 5.1 analog inputs: Panasonic for 30.00CAD and Pioneer for 49.99CAD.Edit: all-analog chains are still easy to repair...

author: MathWizard
author_rank: Super Contributor
timestamp: January 14, 2024, 01:33:05 am
content: Well I went to the pawn shop and got a Denon AVR-2802, 6.1/7.1 CH's, it's meant for 6-8ohms. I'm just setting it up. For now, I have very low power, 8-15W, 4 ohm LR/Center/RearLR speakers. I've read that it should be ok, since I'm not going to turn it up any amount.My subwoofer speaker is 25W 4ohms. Until I just cut it's cable, it was powered from my Logitech 5.1ch system (which I partially rebuilt a couple of years back). I see on the AVR2802, there is no speaker output for a subwoofer, only an RCA output for an amp inside the sub. If I'm barely using any power anyways, might it be ok to plug the bare sub-speaker into the subwoofer pre-amp output ?Otherwise I'd want to disable a bunch of my logitech system, if I was going to use it still as the amp for the woofer. That is until I get some proper bookshelf speakers, and a better sub w/ an amp.https://ia801702.us.archive.org/15/items/manualsbase-id-431554/431554.pdf

author: themadhippy
author_rank: Super Contributor
timestamp: January 14, 2024, 02:07:01 am
content: Quoteyep thats pretty standard, think ive only seen 1 av receiver/amp that had a built in amp for the subQuoteyou could,but you wont hear anything, its a line level output

author: coromonadalix
author_rank: Super Contributor
timestamp: January 14, 2024, 02:16:25 am
content: yep you need an amplified sub for the line out

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 12:22:30 pm
content: Quote from: coppice on January 13, 2024, 06:14:42 pmNope. Those aren’t RGB inputs, they’re component video, which is not the same thing. Yes, the component videojacksare colored red, green, and blue, but they aren’t carrying RGB signals.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 14, 2024, 12:45:16 pm
content: @ Tooki pls correct your sentenceYPbPrYPbPr or Y'PbPr, also written as YPBPR, is a color space used in video electronics, in particular in reference to component video cables. Like YCbCr,it is based on gamma corrected RGB primaries; the two are numerically equivalent but YPBPR is designed for use in analog systems while YCBCR is intended for digital video.Wikipediathey are RGB, but morehttps://techyoulike.com/what-do-y-pb-and-pr-stand-for/

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 12:53:03 pm
content: Quote from: MathWizard on January 13, 2024, 07:25:08 pmQuote from: Zoli on January 13, 2024, 11:09:00 pmIf there is input lag from digital inputs on an AV receiver, that’s due to a poor design, not an inherent lag in the format. According tohttps://www.techpowerup.com/forums/threads/the-problem-with-the-latency-lag-and-5-1-audio-out-and-the-modded-drivers.264461/page-2,Denon receivers of the 1900 series I mention above have input latency on digital of between 0 and 2ms. Adding surround decoding (regardless of whether analog or digital input) adds up to 20ms. That is one single frame of 50fps video, maximum.It sounds like the surround encoders on PCs add a lot of latency, unfortunately. So optical digital stereo would work well since that can be transmitted as uncompressed audio, but the only way to get uncompressed 6-channel audio is over HDMI.So in practice I agree with the recommendation of just using a cheap used receiver with external multichannel inputs, connected to the analog multichannel outputs of your sound card.

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 01:00:59 pm
content: Quote from: coromonadalix on January 14, 2024, 12:45:16 pmThere is nothing for me to fix: my statement is absolutely correct as originally worded.“RGB input” means an input that accepts a red channel on one signal line, green on another, and blue on another, and sync either embedded in green (typically) or on individual lines. Examples of this are VGA and the optional RGB support in SCART.If you connect an RGB signal to a component video input, you’ll get garbage, because component video is not RGB video. It getstransformedto RGB at some point in the playback chain, but it’s not RGB at the input, which is what we are talking about.

author: coppice
author_rank: Super Contributor
timestamp: January 14, 2024, 03:01:02 pm
content: Quote from: tooki on January 14, 2024, 12:22:30 pmThat actually depends on the mode they are in. They can be RGB or one of the corollaries, like YPbPr. Those corollaries are just a rehashed gamma corrected version of RGB.

author: MathWizard
author_rank: Super Contributor
timestamp: January 14, 2024, 04:02:59 pm
content: Ok at some point I'll want to try the digital stuff, and even try using audio over HDMI or something else without compression.Ok I had it working last night, after cutting open my RCA speaker cables, I had all 5 regular speakers working, with EXT. IN selected. I'm not sure of all the other settings, but things like front/rear levels were all set to 0, and still are.Yeah if the preamp is just some small signal amp, yeah into 4ohms, I should not have hooked it up, but I left it over night, and still had audio this morning.But then I turned off the AVR, and wired the sub-woofer back into the Logitech amp, and wired the sub input on the Logitech, to an RCA cable, all with correct polarity, and plugged that into the pre-amp RCA woofer jack.But now since turning it back on, I can't get any audio output. I've repeatably set the input to EXT. IN, my soundcard and windows show they haven't changed in the few minutes it took to hook it up. All the cables/wires are still connected. Sweep to max volume, muted/un muted, nothing. I hear lot's of relays working, maybe some are not.I hope this isn't a real problem, but after searching around, and reading the instructions, and using the remote too, I don't get why it's not working.The AVR display lists EXT. IN as input, it lists another thing beside it sometimes, like TV/DBS or Tuner. It was on TV/DBS since it was working, and I've had it back on that too, now. I've tried AUTO, it flips through stuff but it didn't pick the EXT in as input, even though it should have the only signal.I only have till tomorrow to return if I don't want to try fixing it. Surely this is just some setting thing tho please

author: coppice
author_rank: Super Contributor
timestamp: January 14, 2024, 04:26:08 pm
content: Quote from: MathWizard on January 14, 2024, 04:02:59 pmAudio over HDMI avoids the compression delays that plague most digital options available on modern equipment. The display may introduce delays in HDMI audio, to match the delays it introduces in the video for smoothing purposes. However, if you want responsive video you need to put the display in its low delay gaming/PC mode, and delays won't be added to the audio or video. The HDMI audio delay is really no worse than any other PC to speaker/headphone pathway.

author: MathWizard
author_rank: Super Contributor
timestamp: January 14, 2024, 04:34:56 pm
content: This has optical audio, so I can try that too if I find a cable.But when I turn off the AVR, and turn it back on, the STBY LED blinks a bit while the AVR checks different inputs, it settles on the correct EXT.IN and still TV/DBS as video I guess, and then I hear a relay click, and around that time the STBY LED stays solid. But still no sound.

author: themadhippy
author_rank: Super Contributor
timestamp: January 14, 2024, 04:37:19 pm
content: try connecting your logitec system to the pc to confirm youve still got audio coming out of it,plugging and unplugging things may have confused it.Also with nothing plugged into the av amps inputs crank the volume up ,plug in a phono lead and touch the center pin with yer finger ,you should hear a healthy buzz out the appropriate speakerQuoteDont that mean its in standby? hit the standby button an see wot happens

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 06:06:56 pm
content: Quote from: coppice on January 14, 2024, 03:01:02 pmUmmm…. No? I checked the manual of your receiver to make sure, and nope, no such setting. Nor have I ever heard of any device with RGB signals on RCA jacks from the factory. (I have seen it with RGB mods by retro gamers.) “Component video” with no further qualifiers means YPbPr, which is not interchangeable with RGB. You can convert between them, but they’re not the same thing. If they were the same thing, you could just connect the signals and have the correct image. You can’t, so they’re different. (I can’t believe I need to spell this out in this thread more than once.)You’re probably thinking of HDMI, which does offer various color models.

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 06:14:40 pm
content: Quote from: MathWizard on January 14, 2024, 04:02:59 pm1. Plug headphones into the receiver to see if audio is getting in. I think this should work even when using the external inputs.2. Have you turned on Speaker A (or B, depending on which you used)?

author: MathWizard
author_rank: Super Contributor
timestamp: January 14, 2024, 06:39:54 pm
content: Yeah it's not the PC, I hooked a clock radio to the center output. The AVR speaker setup is correct, I tried phono with an RCA cable and heard nothing at all.I've glanced at a few threads on repairing these, already I see mention of reflowing a lot of solder joints, and some chip's losing gnd pin connections. Other's with failing memory chips.But yeah it is supposed to just pass through the EXT.IN audio, so it's probably not getting passed by some buffer.I don't expect the pawnshop to lower the price if I bring it back and show it's not working, on some functions at least.Pretty soon I'll open it up, I just wish it wasn't so big/heavy.

author: MathWizard
author_rank: Super Contributor
timestamp: January 14, 2024, 11:55:20 pm
content: With a signal tracer, I can hear the signal at the 2nd chip the EXT IN channels go to, which is the serial controlled volume controller, TC9459N, the signal is on a cap, and the chip, but I can't find it leaving, so I guess I'll have to look with a scope if the CLK and any serial data gets sent to it.

author: Haenk
author_rank: Super Contributor
timestamp: January 15, 2024, 02:30:23 pm
content: Honestly, buy a working one. These are dirt cheap, certainly available below 100 EUR. And you really don't want getting into repairing these. Disassembling and assembling alone likely takes you a couple of hours, plus searching for errors, plus spare parts (if available). I have a couple of non-working Denon amps stored away, "fix later". Haha. No way. That's just a waste of time, and the working ones are worth less than the parts alone.Audio delay is IMHO a non-issue, unless you have superhero-abilities, you will not notice it. I'd suggest using TOSLINK (optical), no ground loop, tiny cable etc. - and likely the DAC in your amplifier is better than the one on your soundcard.

author: bingo600
author_rank: Super Contributor
timestamp: January 15, 2024, 02:55:10 pm
content: I have used a Sony STR-DE435 , before i "went digital"It was a nice Analog reciverhttps://www.ebay.com/itm/354694460193?

author: MathWizard
author_rank: Super Contributor
timestamp: January 15, 2024, 05:37:42 pm
content: I collected some snapshots of the serial data, I'm not sure what the format really is. The datasheet only talks of 32-bit segments, and I think they are only written to the chip, when followed by a strobe pulse.But there's also gaps, IDK if those are nulls and that's what the datasheet calls "0", but looked at another way, there are clock pulses in place of the "0"Here's and example of changing the volume from the lowest which is displayed as ---, I think that =-89dB in this chip. And I turned the knob up 1, to -88dB. The code for 88 would look like 0001101 with MSB last.In the xxx23 pic, if the message did start with D01, then it does give 88dB for left and right CH's inside the chip. A,B,C are 0, S0 and S1=0, and chip select would be 8. But then the strobe signal is way to the right of it, so doesn't that mean the above is wrong ?But it works for other volume levels too, where I can see the L/R volume level as D01-D07 and D11-D17 in the 1st 2 blocks of the signal.Working back from the blue strobe signals, doesn;t seem to work nice, and then there's the gaps in the clock, that I'm not sure what they mean or count for.

author: wasedadoc
author_rank: Super Contributor
timestamp: January 15, 2024, 05:53:43 pm
content: Quote from: coppice on January 14, 2024, 03:01:02 pmNo they are not. You are incorrect on two counts. Component video is luminance and two colour difference signals. Furthermore RGB signals are already gamma corrected

author: MathWizard
author_rank: Super Contributor
timestamp: January 15, 2024, 11:23:55 pm
content: Just counting clock signals as a timing event, and ignoring any clock gaps seems to almost work. Any volume I've tried, the 1st 2 blocks match the dB code. But one of the 4 dummy bits in the 32bit code, I've seen as a 1 a couple of times. And I've also captured the clock signal staying high for probably 20us, normally it's high for ~3us out of 10us period. I thought it might be my scope but my better one sees it happen too.Also I've never once seen the code tell the chip to enable either variable resistor banks, A-B-C, 'volume select data', which do the attenuation, it's some R2R network with switches.So my guess right now is that those bits being all set to 0, is why the chip is not passing the audio. I can see if the TC9459N is doing the same thing, then I'd have to start taking boards off to look at the XTAL and clock and data source on another board.

author: MathWizard
author_rank: Super Contributor
timestamp: January 17, 2024, 06:43:40 am
content: I took most of the boards out of it and cleaned it up. Then made -40dBV attenuators for all 5.1 channels, to stand-in as the 2 volume controller chips. I was using -22dB when it worked, and that should be -40dB if it goes from -70 to +18dB. The controller chips go from -90 to 0dB, then the AVR calls it up to +18.Both chips are still in place, I just made another little circuit board, and wired it in/out.And now at least, phono, and L/R channels have some output again. I could see the Rear L/R and center ch signals showing up at my PCB, so they must be getting mutted or something farther along. Right after the volume chips are some op-amp's, so I wonder if they do some muting by just grounding aome op-amp inputs.But with my 47k:470 dividers, and my PC set to max, it's not loud enough, and still only frontL/R seemed to work tonight, but that's an improvement. and a few steps closer to full working analog 5.1CH audio.