Pioneer VSXD704S Very Distorted Sound

[@zx8401ztv]

Smashing, well done dave, the damp finger test made me smile 😀 It did sound unbiased but there are power supply problems that can cause that as well. I repaired an old sharp double tape deck millions of years ago, one channel was distorted. Yep half way down the head preamp a coupling cap had gained resistance. It wasn't an electrolitic or ceramic, polymer i think. I never had a poly fail untill that one. The test audio amp box i threw together back in 2002 was ideal for traceing, Simple tests 😀

[@izzzzzz6]

The finger technique, one i use myself. I used to decode old ford head units with a wet finger, like an early version of the flipper pro. However the other day i was messing around with a DAC on a Yamaha SSA with my finger like this and must have picked up some voltage from somewhere. i was running a really nice speaker which is pretty stupid for testing with and the dc blew the coil right out of the magnet gap and transformed the coil into an oval shape. Amazingly i was able to disassemble the driver, bend the coil back to circular shape and i managed to reseat the cone with zero rubbing. Phew. A close one for a very nice speaker! Time to pick up another el-cheapo for testing with. In the end i got a new DAC from alli and it now works in all modes not just 2ch stereo. I bought a nice Pioneer that is doing exactly this distortion but can't find a schematic for this one. It's something in the pre amp section i think, didn't have time to look closer yet but he thought it was DSP.

[@hansu-nihon]

8:52 The small transistor legs are damn close together.😯 Glad you corrected it.🙂

[@12voltvids]

Yeah they're pretty close damn near touching

[@collindsouza4735]

You are just awesome. Love your troubleshooting techniques.

[@imabean9016]

i have no idea what ur doing but i love to watch

[@12voltvids]

Let you in on a little secret. I have no idea what I am doing either.

[@jaceknasalski1422]

@@12voltvids 😂

[@tacofortgens3471]

​@@12voltvids 🤣

[@mdzacharias]

I did Pioneer warranty service for over 20 years, the 2SC2705 and 2SA1145 transistors were known failure items on these. Usually caused noise and static, but not exactly your symptom that I can recall. I would replace all of them in a particular unit, about 20 in all. They never came up with an improved replacement.

[@wilfredorivera6549]

✌️🤨very instructive video,of tracing the problem,very good💯💯

[@michaelethangross3395]

Pioneer made some really nice AV receivers in the early 90s like the VSX D1S VSX D901S D702S etc that had decent power amp sections preamp outputs etc but thereafter quality started slipping.

[@ashoknair8993]

Thank you ..learning something new today

[@rbtgmnstcs]

I enjoy watching your videos. It would be nice to get zoomed in a bit further to be able to see the soldering. I would use a bit more IPA, toothbrush for cleaning and more soldering flux for better flow/surface tension of the solder. At work I'm using the JCB Tools soldering stations and tools, and I must say that it's a joy working with their stuff. Maybe a bit too expensive, but for everyday use, it'll improve "joy factor". I'm looking forward for new videos next year. Happy new to you!

[@jamesbaker429]

Lift the lid everyone is different ,at least access just mechanical but oh so fiddly components you can change rather then minimal chips,fixable with your expertise, it's what makes you so watchable and hopefully you can enjoy it too on some level.

[@haterademedia6088]

Very informative. Nice video thank you.

[@sand0077]

That sound reminds me of popcorn popping, think I'll go pop me up a bowlful! 😆

[@Sta2200]

Question "at the 24 or so minute in the video...what was the name of the electronic tune...you were playing...when you got the channel fixed ?? I like it...want to hear more of it... Thanks..

[@12voltvids]

It is a music bakery royalty free track. You can play all the tracks on the site to figure it out.

[@erickvond6825]

I'm curious as to how you feel about Harmon Kardon and Carver amps. I've used both and had no trouble from them. I've also had the fortune to buy some old McIntosh amps for $30 at a yardsale which I restored. They relly only needed to be recapped. Hell of a deal.

[@12voltvids]

The old two channel Harman kardon we're good the multi-channel ones not so much I have one that I paid off a lot of money for and it did not last. Carver also made some very good equipment and years gone by I don't know much about their modern stuff though. I haven't seen much of it so it must be pretty good it certainly not breaking down. I've got a Crest audio myself and it just sounds absolutely amazing

[@richardfriedlander8281]

Dave could you tell us which model Weller soldering station you are using? Thanks.

[@tedevans2095]

I need a surround board that has 3 sets of the red and black push tabs for the speaker wire connection. I have a Sony STR-SE491. Please help if you can.

[@alexanderherget6303]

A pie in ear. Good work and nice vid.

[@12voltvids]

When someone throws a pie at you and you get some in your ear

[@jeffadams5510]

Ohhhhhh yeah, the old pioneer wind tunnel units. Been through a few of those and the worst I saw needed all new drivers and maybe even some pre drivers cuz they ran so hot. I repaired many bad solder connections which fixed the unit for a short time, then the transistors themselves became intermittent. Frigging nightmare but nice units when running correctly.......

[@12voltvids]

Yes they are a joke.

[@Jammerk40]

What is your most favorite brand of receivers?

[@tacofortgens3471]

Sansui 9090 is his favorite I believe

[@blade3120]

Hi dave the last crhstmass i am lucky find my bilding amplifier pionner sa-6500 2! Put in the plug i hear it very distorted sound he falut NOT FINAL TRAZISTORS OR DRIVERS TRANZISTOR! HE FAULT THE CIRCUIT PROTECTOR TO HAVE 2 FUSE IS BLOWN! PUT THE SPESIFIC FUSE TO NEED! The model pioneer to have have plug american but he have voltage selector! Greece use 220 or 230vac! put the voltage selector in 240vac! work perfect the amplifier! Greece athens!

[@ashoknair8993]

My pio vsx D 701s left channel is distorted....please share your thoughts ...

[@tacofortgens3471]

This problem

[@JaypiTechPHOfficial]

I remember this same pioneer AVR. same problem. but the worst is, the Protect pin accidentally touched the Collector pin on transistor. leading to trigger protect on the panel board. what a bad design.

[@12voltvids]

Like all pioneers it's a piece of crap. It is a stupid design I don't know if you guys told her sister not but there are no insulators between the transistors and the heat sink so the heat sinks since they're all in piano on one heat sink at all PMP on the other the heat sinks itself rise to the potential of whatever is on all the collectors which are all parallel connected so you've got potential of the two heatsinks that are only separated by a couple of millimeters help together with the fat and stuff there's the potential that if you were to touch both heat sinks at the same time you would have the full it was about 40 volts or so potential across between the two of them so you could get a jolt if you were to touch both heat sinks at the same time when it was active

[@Calpe1704]

Got a VSX-708RDS with a similar problem of distorted audio r/h channel. Any ideas anyone?

[@흑석김용호]

bad connection bias problem Overheating due to bias problem Solder cracks due to overheating

[@sirtainlee8725]

Nice causation sequence.

[@stevenmann9769]

I would say that some Pioneer stuff is junk. I do like their laserdisc units though.

[@12voltvids]

Laserdisk units are the exception. They made some good ones and I have several of them.

[@markmarkofkane8167]

Sounded like a bad connection.

[@jlev505]

1990s Sony and pioneer car audio amps have very similar looking boards to that. The boards have many problems with broken traces and cracked solder joints. Very time consuming flowing the boards. That’s usually where the faults are in those brand amps. The old Sony xm-2100g and xm-5046 do sound amazing and are worth the trouble! The old made in Japan amps all have similar board like Sony, denon and pioneer. Alpine had much better boards.