• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Let's See Your Great JVC Gear!

Just got this RX-707V for fun to try out for not that much of cost. Surprisingly it does sound nice. I also got some other JVC like VN-900, AX-1100 and Z911 and I don’t think it play less than the others I mentioned here, to my ears. Again I don’t have trained ears, just like to try things out.
Plus it got this SEA with graphic spectrum jumping up and down with music and you can fine tune what you like. Just a lot of fun watching it too. Some people might not like it because of distractions but it is just fun for me for now.

IMG_1476.jpeg
 
just brought this home today. took about an hour to repair. had 2 bad outputs so i replaced all 4. that's all it took. nice sounding 12wpc.

there's some c458 i need to get rid of and the obligatory recap of course. and some bulbs.

20240524_143452.jpg

20240524_143458.jpg

i like it.

finding other stuff wrong with this thing.
 
Last edited:
painttoad said:
just brought this home today. took about an hour to repair. had 2 bad outputs so i replaced all 4. that's all it took. nice sounding 12wpc.

there's some c458 i need to get rid of and the obligatory recap of course. and some bulbs.

View attachment 3209073

View attachment 3209075

i like it.
Click to expand...
I have one of these. Had to replace all those little source and speaker bulbs. Did a recap, replaced some transistors and built new sides for the case since much of the veneer was coming off.
 

Attachments

  • IMG_20220408_091246454_HDR.jpg
    IMG_20220408_091246454_HDR.jpg
    95.7 KB · Views: 14
Byron Boldt said:
Had to replace all those little source and speaker bulbs. Did a recap, replaced some transistors and built new sides for the case since much of the veneer was coming off.
Click to expand...
pretty much what i'm doing. veneer is not in bad shape but not perfect. i will probably make hardwood sides for it vs. veneer altho i can go either way with what i have on hand.
 
Richard P said:
I probably measured output power but didn't record it and can't recall what It was. At the time I worked on it I didn't have the capability to do THD so that wasn't measured. Here are some notes I posted back then:

JVC VR-5505 Notes
Click to expand...
yeah, i've been thru every thread i can find on the internet.

i just can not get much more than about 8.5wpc then the signal clips, power supply sags and distortion climbs.

i've got a few more things to look at but i'm not very confident of getting another 3wpc. lol.

i know it's botl but i just want it to be right.

Annotation 2024-05-26 161708.png

it's post 1974(as far as i can find but no definite year of sale) so i wouldn't expect too much exaggeration.
 
Well the heatsink looks awfully small.. The tranny looks a lot more promising, but then again it has to run a lot of bulbs right? I'm absolutely loving that display though! What is the capacitance of the main buffer caps?
 
Okke 70s said:
Well the heatsink looks awfully small.. The tranny looks a lot more promising, but then again it has to run a lot of bulbs right? I'm absolutely loving that display though! What is the capacitance of the main buffer caps?
Click to expand...
14 bulbs are on their own separate ac winding.

filter caps are 1000uf each.

it is nice looking and it is sounding very nice but .......
 
Richard P said:
Filter caps OK? Only 1000 uF . . .
Click to expand...
brand new as are the bridge rect. diodes. outputs replaced with ksd526. all silicon replaced besides 6 diodes that are getting shotgunned next session.

it had 2 bad outputs and i thought this would be a wham bam repair:rflmao:

i just bought this because it was cheap af.
 
Maybe try it with an external preamp to rule out/confirm the problem is in the amp . . . Interesting to find a pre-out/main-in on such a low end receiver.
 
Richard P said:
Maybe try it with an external preamp to rule out/confirm the problem is in the amp . . . Interesting to find a pre-out/main-in on such a low end receiver.
Click to expand...
same either way.

i really did not mean this to turn into troubleshooting, i just wanted to know if this unit really pushes 12wpc or if i was chasing my own tail.

but thank you.
 
painttoad said:
it had 2 bad outputs and i thought this would be a wham bam repair:rflmao:
Click to expand...
Ah, the blind optimism of an enthusiast! I suppose that is what keeps us buying those broken down old machines.

Anyway, considering the small outputs, tiny heatsink, ambiguous tranny output and 1000uf caps.. 12 WPC might be ambitious. But I think he should still make it, right? I would definitely put in 2200uf replacements, assuming the diodes you put in got plenty capacity to deal with that.

I understand now you can also use it as a tuner-pre amp, with something else doing the heavy lifting. That might not be a bad idea. Perhaps they figured you could use it as stand alone, untill you saved up to add a Poweramp and bigger speakers?
 
I've had these for years, they are both operational (ran when parked lol). They are pretty much identical save for small details. The top one is the 5444 (no 4vr prefix) from 1971, and below is the 4vr 5445. Both had scratchy pots but otherwise sound great with power. Need to give them the love they deserve ! Also have a service manual in CD format I need to convert and post here...
 

Attachments

  • 20240117_190139.jpg
    20240117_190139.jpg
    117.7 KB · Views: 19
Okke 70s said:
Anyway, considering the small outputs, tiny heatsink, ambiguous tranny output and 1000uf caps.. 12 WPC might be ambitious. But I think he should still make it, right? I would definitely put in 2200uf replacements, assuming the diodes you put in got plenty capacity to deal with that.

I understand now you can also use it as a tuner-pre amp, with something else doing the heavy lifting. That might not be a bad idea. Perhaps they figured you could use it as stand alone, untill you saved up to add a Poweramp and bigger speakers?
Click to expand...

i buy broken and repair them to keep me sane on disability. i sell what i don't want(not often enough) and keep what i want.

the goal of this unit was to be able to sell it to someone as a cheap bedroom or office receiver.

i have plenty of personal heavy hitters. :)

the thought had crossed my mind to go with 2200uf caps but if this power supply can't supply the power to get 12wpc, once the larger caps are depleted the power supply will just have to work that much harder to run the amp and try to recharge the caps so i do not think that is viable.

maybe i will try that as an experiment to see how much, if any power is lost.:idea:

i have had a couple units from this era that came up just short of rated power. i can attribute most of that to my measuring setup but i felt that 30% less was/is extreme.

the only history i have of this is that i bought it from a guy that bought it from a tinkerer's estate.

if there is a fault, it should not be this hard to find as there are only so many components common to both amp channels.:dunno:

i won't give up anytime soon.
 
You must log in or register to reply here.
Back
Top Bottom