Author Topic: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990  (Read 7003 times)

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Offline wnorcott

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Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« on: October 07, 2011, 03:18:35 PM »
I just bought this 1990  Yamaha VR5000 a couple days ago from a local music store for the obscenely low price of $67 and thought I would share it in case anyone comes across one.   The VR series was Yamaha's answer to the Roland JC Jazz Chorus series guitar amplifiers, only the Yamaha were actually bit better spec'ed and were more expensive than the Roland (and hardly advertised) so never really caught on.   They were not big sellers when new and are almost completely forgotten now that Yamaha has been out of the pro audio guitar amplifier market for many years. This amp is an amazing sleeper.  The VR6000 was 2 x 12" speakers with 2x50 Watts rms stereo amps.  The VR-5000 that I got is 1x12" speaker 100 Watts rms.  Size is about 21" x 21" x 11" and the original weight was 45 pounds.  It is like a Jazz Chorus but cleaner and with more sounds but also more complex to operate. 



Although the VR5000 lacks "chorus" it more than makes up for it in tone controls, having 2 separate channels with A/B switching with 2 parametric EQ's per channel.  The tone controls on this are pretty wide range and are extremely "clean" as apparently they used the same components and transformers as on Yamaha hifi stereo amps. It is actually a much quieter amp than the JC120.  There is no hiss at all you cannot even tell when it is turned on unless you plug in a guitar.  No speaker thump when you power it on. There is also effects loop send/receive jacks on the back as well as line out, and a headphone jack on the front.  Another nice touch is it has a 250 Watt grounded AC outlet on the back.

100 Watts rms into 8?

Pull BOOST    +10 dB boost
Pull FAT       +10 dB boost at 400 Hz
TREBLE        ±15 dB at 5 kHz
(Pull Bright; +12 dB boost)
MIDDLE +10,    -5 dB at 800 Hz
BASS       +5, -15 dB at 80 Hz
P.EQ FREQ     P.EQ1 100 Hz - 1 KHz
P.EQ2  800 Hz – 5 kHz
P.EQ LEVEL   ±15 dB variable

It does not have a Distortion knob which is just as well but there is GAIN and VOLUME controls so as you up the GAIN it gets a nice crunch tone that is quite nice actually.

It turns out some previous owner had replaced the Yamaha speaker with a Electro-Voice EV Force 12 which is no longer in production but essentially the same speaker as the EVM 12L that they brought back into production, only with 150 Watts rms power handling for the Force 12 vs. 200 rms for the 12L, same 60 Hz - 7 KHz usable frequency range.  The efficiency of the Force 12 is 101 dB/1W at 1M and sound pressure level is 119 dB at 150 watts.  It is a whopper with a 10 pound magnet & cast aluminum frame and weighs 17 pounds.

Since I got it I shaved the "pills" off the grille cloth so it looks much nicer and cleaned it up so it looks a bit less like a 20 year old amp.  It was marked way down as a "manager's special" probably because the reverb didn't work and made a horrific humming sound if you turned the Reverb knob up -- and the knob was up when I saw  it so the amp was unusable in the store.  I am sure they had no idea what was wrong with it.  It turns out these amps had an unusual electronic footswitch to turn on the reverb and channel switching.  I was able to reverse engineer the foot pedal partially and got the Reverb to come on, that and a little Deoxit on the connectors to the reverb tank and reconnected connected the ground wire from the reverb tank that was had come off and it works great.  The reverb is very nice on this amp very quiet and with good sound both channels share the reverb.  People's taste in reverb varies, this is a long-period reverb and the reverb unit is about 19" wide.

The sound of this amp is really excellent, extremely loud and clean sound and a huge variety of tones. Of course it is impossible to describe tone in a forum. The 2 EQ's per channel really change the shape of the sound.  It also makes it a bit complex this is an amp you want to write down the settings.  I set the 2 parametric EQ on flat then set the regular tone controls (treble/mid/bass), then adjust the EQ's one at a time a little at a time.  Since I just got it and the GR-20 what I am doing is, on channel A I set all the tone controls flat then raise the treble a bit for the synth.  Then on channel B I set it for a really warm clean guitar sound and switch the channels when I switch the guitar to "guitar only" setting on the with S1.  When I am just using straight guitar I use the MIX jack of the Godin xtSA and I set 2 completely different sounds on channels A and B and switch them.   

Bill
I play old school because I am old school.

Offline mbenigni

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #1 on: October 11, 2011, 09:58:43 AM »
Great post.  Very informative.  Thanks!

Offline wnorcott

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Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #2 on: October 20, 2011, 01:39:34 PM »
Thank you.  I believe I am getting very close to reverse engineering the channel A/B & reverb on/off footswitch for the Yamaha VR5000 amp.  It uses electronic switching inside the amplifier to control both of these functions even though the switch box connects to the amplifier with just a simple mono guitar cord: these are not simple on/off switches like on most guitar amplifiers.  There is a network of resistors inside the pedal that sends a different level of current back into the amp depending on which switch combination is pressed.   That is how they can control multiple function. I think I am closing in and if I get my idea to work I will post the plans here so anyone can build one.  Yamaha were good sports and very cooperative but even the Yamaha amplifier guy says he has been looking high and low himself for a schematic for the VR-series foot switch and never has seen one for it.
I play old school because I am old school.

Offline Elantric

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #3 on: October 20, 2011, 02:57:53 PM »
See attached - this is all I could dig up
Just the owners Manuals


My guess is the Amp uses a Resistive "Window comparator" circuit, that activates specific functions based on the resistance across the Tip and Shield of the mono  Footswitch jack. 

I would:

1 ) Measure the DC voltage between the Tip and Shield on a 1/4" guitar cable connected to the Foot switch jack. Write it down.

2 ) Grab several different value resistors, 1K, 5K, 10k, 47k, 100K  -  and momentarily connect a Resistor between the Tip and Shield of a 1/4" guitar cable connected to the Foot switch jack and observe the amp and see if it changes channels or enables the Reverb. a magic combination should enable each function.

My hunch - Inside the amp is a variation on this type circuit - they use  1/4" jack "Tip" contact at the "Test Probe" Input , and eliminated the TTL / CMOS selction - not needed for the proprietary Yamaha  foot switch control.

« Last Edit: December 19, 2014, 01:20:55 PM by Elantric »

Offline wnorcott

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Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #4 on: October 20, 2011, 08:56:59 PM »

Yes thanks, that is what I thought it would be too.   I was able to reverse engineer the switch after finally locating the VR5000 schematic  and working it backwards.  The Footswitch In jack on the front panel is a switched jack that bypasses the Channel Select button on the front panel.  The guitar cord send a fixed DC voltage from the amp to the footswitch.  There is a fixed resistor in series with the foot switches (which are wired in series) and each switch bypasses one of two different-valued resistors (which also serve as the current limiting resistors  the LEDS). Closing a switch bypasses its resistor/LED and causes varying current back to a transistor inside the amp which converts it back into a stepped voltage; the voltage is sent to a NJM2901 quad comparator IC that detects the voltage thresholds and then does the switching.  Like you said it was just a matter of figuring out the window to trigger the comparators.

The switching is absolutely noiseless too, and no bounce, and now I have both the Channel A/B switching and the Reverb on/off functions working as they should. 

Here it is switching the channels:

(channel B)



(channel A)



Here is the homebrew footswitch again after I labeled the functions:






Bill

I play old school because I am old school.

Offline mbenigni

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #5 on: October 21, 2011, 08:35:42 AM »
That's awesome.  $67 and some elbow grease - you must be so happy with this purchase!

"Amazing sleeper" is a good description of so many Yamaha products.  I'm a long-time fan of everything from their monitors to their motorcycles.  :)

Offline Elantric

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #6 on: October 21, 2011, 09:15:38 AM »
The controls remind me of a 1980's Yamaha G100 , with the Fat control. I bet Paul Rivera had a hand in your amp's design.

Offline wnorcott

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Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #7 on: October 21, 2011, 11:55:49 AM »
Yes, Paul Rivera designed this amplifer.
I play old school because I am old school.

Offline laband

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #8 on: January 17, 2012, 02:31:57 AM »
hello, if anyone has a schematic for the VFC-3 for Yamaha VR-6000 please send me

Offline wnorcott

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Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #9 on: January 18, 2012, 07:55:43 PM »
Hi

I have not been able to email you so I will post my schematic here hope it works

Bill

I play old school because I am old school.

Offline laband

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #10 on: January 19, 2012, 01:12:30 AM »
thank you so much

Offline Steezo

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #11 on: February 03, 2012, 05:26:06 PM »
Hello, I also acquired a VR5000 in very nice conditions, but it won't power up.  :-\

All the components inside seems ok, no burnt or exploder resistorsS or other, so I'm wonder if someone have a schematics or a service manual so I could find the problme.

Many thanks in advance, Steezo.

Offline Elantric

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #12 on: February 03, 2012, 05:39:10 PM »
Only have the owners manual - see attached
« Last Edit: September 13, 2015, 12:07:03 PM by Elantric »

Offline Vr6000

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #13 on: September 04, 2016, 07:00:20 AM »
I just bought this 1990  Yamaha VR5000 a couple days ago from a local music store for the obscenely low price of $67 and thought I would share it in case anyone comes across one.   The VR series was Yamaha's answer to the Roland JC Jazz Chorus series guitar amplifiers, only the Yamaha were actually bit better spec'ed and were more expensive than the Roland (and hardly advertised) so never really caught on.   They were not big sellers when new and are almost completely forgotten now that Yamaha has been out of the pro audio guitar amplifier market for many years. This amp is an amazing sleeper.  The VR6000 was 2 x 12" speakers with 2x50 Watts rms stereo amps.  The VR-5000 that I got is 1x12" speaker 100 Watts rms.  Size is about 21" x 21" x 11" and the original weight was 45 pounds.  It is like a Jazz Chorus but cleaner and with more sounds but also more complex to operate. 



(Image removed from quote.)

Although the VR5000 lacks "chorus" it more than makes up for it in tone controls, having 2 separate channels with A/B switching with 2 parametric EQ's per channel.  The tone controls on this are pretty wide range and are extremely "clean" as apparently they used the same components and transformers as on Yamaha hifi stereo amps. It is actually a much quieter amp than the JC120.  There is no hiss at all you cannot even tell when it is turned on unless you plug in a guitar.  No speaker thump when you power it on. There is also effects loop send/receive jacks on the back as well as line out, and a headphone jack on the front.  Another nice touch is it has a 250 Watt grounded AC outlet on the back.

100 Watts rms into 8?

Pull BOOST    +10 dB boost
Pull FAT       +10 dB boost at 400 Hz
TREBLE        ±15 dB at 5 kHz
(Pull Bright; +12 dB boost)
MIDDLE +10,    -5 dB at 800 Hz
BASS       +5, -15 dB at 80 Hz
P.EQ FREQ     P.EQ1 100 Hz - 1 KHz
P.EQ2  800 Hz – 5 kHz
P.EQ LEVEL   ±15 dB variable

It does not have a Distortion knob which is just as well but there is GAIN and VOLUME controls so as you up the GAIN it gets a nice crunch tone that is quite nice actually.

It turns out some previous owner had replaced the Yamaha speaker with a Electro-Voice EV Force 12 which is no longer in production but essentially the same speaker as the EVM 12L that they brought back into production, only with 150 Watts rms power handling for the Force 12 vs. 200 rms for the 12L, same 60 Hz - 7 KHz usable frequency range.  The efficiency of the Force 12 is 101 dB/1W at 1M and sound pressure level is 119 dB at 150 watts.  It is a whopper with a 10 pound magnet & cast aluminum frame and weighs 17 pounds.

Since I got it I shaved the "pills" off the grille cloth so it looks much nicer and cleaned it up so it looks a bit less like a 20 year old amp.  It was marked way down as a "manager's special" probably because the reverb didn't work and made a horrific humming sound if you turned the Reverb knob up -- and the knob was up when I saw  it so the amp was unusable in the store.  I am sure they had no idea what was wrong with it.  It turns out these amps had an unusual electronic footswitch to turn on the reverb and channel switching.  I was able to reverse engineer the foot pedal partially and got the Reverb to come on, that and a little Deoxit on the connectors to the reverb tank and reconnected connected the ground wire from the reverb tank that was had come off and it works great.  The reverb is very nice on this amp very quiet and with good sound both channels share the reverb.  People's taste in reverb varies, this is a long-period reverb and the reverb unit is about 19" wide.

The sound of this amp is really excellent, extremely loud and clean sound and a huge variety of tones. Of course it is impossible to describe tone in a forum. The 2 EQ's per channel really change the shape of the sound.  It also makes it a bit complex this is an amp you want to write down the settings.  I set the 2 parametric EQ on flat then set the regular tone controls (treble/mid/bass), then adjust the EQ's one at a time a little at a time.  Since I just got it and the GR-20 what I am doing is, on channel A I set all the tone controls flat then raise the treble a bit for the synth.  Then on channel B I set it for a really warm clean guitar sound and switch the channels when I switch the guitar to "guitar only" setting on the with S1.  When I am just using straight guitar I use the MIX jack of the Godin xtSA and I set 2 completely different sounds on channels A and B and switch them.   

Bill

Hi there, I'm new here and I need one single information about the Yamaha VR 6000. Can anyone tell what impedance ( in and out) the Reverb tank of this amazing amp is? Mine is broken and must be replaced. Many thanks in advance!! Dieter
« Last Edit: October 13, 2016, 05:31:28 AM by Vr6000 »

Offline Elantric

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #14 on: September 04, 2016, 10:01:31 AM »
If you still have the original reverb tank, often it's a loose spring but the transducer impedance can still be measured with an ohm meter from the RCA phone jack.

If it broke due to loose wire, often you can still measure the transducer impedance directly from any available remaining external electrical contact on the transducer

Post pics

Often there is a part number on a label on the reverb tank
« Last Edit: September 04, 2016, 10:04:33 AM by Elantric »

Offline Vr6000

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #15 on: December 09, 2016, 01:19:48 PM »
Only have the owners manual - see attached

I own an Yamaha VR6000 and already built the VFC-2 ( schematics provided by you)  for accessing the channel switch and reverb on and off.
Since on the VR 6000 there is a chorus in addition, which I can not switch because I don't know the values for the resistors responsible to switch the chorus.

Would be amazing to get them by someone who's an expert. I tried different values but was unlucky to hit the one that works.

Many thanks in anticipation.
Cheers Dieter

Offline shinopshino

Re: Yamaha VR5000 1x12" 100 Watts rms combo ca. 1990
« Reply #16 on: July 24, 2017, 06:26:40 PM »
I also recently purchased at Yamaha VR6000 without the VFC-3 foot-switch array.
I also could not use the reverb or chorus, but looking at the schematic for the vfc-2 it looks like switches in all open position turn everything on.
So I used a dummy mono jack lead and plugged one end into the foot-switch socket.
My reverb and chorus is now controllable from the front panel. Not ideal but until I find a VFC-3 or the value of the resistor in the VFC-3 that controls the chorus, this will do for now.

Cheers.

Tee.
teesquared@outlook.jp

teesquared.info

 

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