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Non ADA Gear => Rack Gear => Topic started by: rabidgerry on March 10, 2019, 04:22:47 AM

Title: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 10, 2019, 04:22:47 AM
Ok guy's I was tube rolling my studio peavey rockmaster yesterday and well during a slightly rushed tube change I pulled the tube in V1 quite early, probably just before it had actually fully went out (went out as in the glow had diminished).

Anyways, I popped a different tube in there to see what it sounded like in that combination with the remaining tubes and the dam rockmaster failed to power on.  Nothing at all, no led, no nearly coming on, nothing.  DEAD!

Any ideas?  Have I killed the Rockmaster?  Would I have blown the transformer may be?
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Soloist on March 10, 2019, 07:57:33 AM
I have to state the obvious first. Did you check the fuse?
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 10, 2019, 08:32:45 AM
Hiya RG,

Try this first, Check F1 first, thats your HT fuse which is a 1A Fast Blow on the schematic. I don't know why they used a fast blow in that position as those resevoir capacitors after the bridge rectifier will pull a lot of initial start up current well beyond 1A at power on.

Second, try this too, test F2 and F3, those are 1A slow blow type, F2 is for your heater filaments and F3 is for your relays. If F2 is blown then your heaters and LEDRD2 (which I suspect is your power on pilot light) won't power up. The rest of the amp circuitry may as well be running ok but with no indication at all that that F2 is blown.

Another thing, F2 and F3 (and F3 possibly) fuses are probably inside, mounted on the power section of the PCB,

There should be also by code/regulations a mains fuse prior to the power on switch and easily accessible without the need to screw the amp apart, your mains fuse. F1 is not it. I cannot see it because the schem PDF is cut a little short to the right hand side.

Let us know how you you get on checking those fuses first, (I kind of suspect that it is F1, and I don't think its your Power XFRMR) but lets not jump to conclusions, bad idea in the electronics game. Take at look at the attachment, I have marked them up in red.

Rusty.

 
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 10, 2019, 08:47:43 AM
I have to state the obvious first. Did you check the fuse?

Hi Soloist,

ok that was the first thing I thought off.  However there are about four fuses to check.  They all looked ok to me.  Stupid question, how do I check?  Use a millimetre and test end to end?

I did check the actual plug fuse and it wasn't that.



Hiya RG,

Try this first, Check F1 first, thats your HT fuse which is a 1A Fast Blow on the schematic. I don't know why they used a fast blow in that position as those resevoir capacitors after the bridge rectifier will pull a lot of initial start up current well beyond 1A at power on.

Second, try this too, test F2 and F3, those are 1A slow blow type, F2 is for your heater filaments and F3 is for your relays. If F2 is blown then your heaters and LEDRD2 (which I suspect is your power on pilot light) won't power up. The rest of the amp circuitry may as well be running ok but with no indication at all that that F2 is blown.

Another thing, F2 and F3 (and F3 possibly) fuses are probably inside, mounted on the power section of the PCB,

There should be also by code/regulations a mains fuse prior to the power on switch and easily accessible without the need to screw the amp apart, your mains fuse. F1 is not it. I cannot see it because the schem PDF is cut a little short to the right hand side.

Let us know how you you get on checking those fuses first, (I kind of suspect that it is F1, and I don't think its your Power XFRMR) but lets not jump to conclusions, bad idea in the electronics game. Take at look at the attachment, I have marked them up in red.

Ádh mór, Rusty.


Hi Rusty hope you are well mate?  Dreading Brexit like myself then?   :facepalm: :facepalm:

You sound like you have a schematic for the Rockmaster is that correct mate?

***edit*** I just realised you posted a schematic with red marks to show me hahaha!  Hang on and I will check those fuses.

Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 10, 2019, 09:04:45 AM
Thank you RG, I'm doing ok at the moment.

RG I got the peavey rockmaster 91 schematic version, I think thats the right one, if not then it should be very similar.


Dreading Brexit like myself then?   :facepalm: :facepalm:,  F-k-n right I am RG, what a pile of f-k-n shit my friend !!
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 10, 2019, 09:11:57 AM
Ok looked up how to test the fuses and from what I can see each fuse is working ok.  There are four in total.  One near the power cable outlet.  I removed each one and then tested with millimetre just as it does on this website.

http://www.swe-check.com.au/pages/learn_fuse_testing.php (http://www.swe-check.com.au/pages/learn_fuse_testing.php)

Jeez I've really killed the rockmaster.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 10, 2019, 09:41:10 AM
I'll get back to you later RG, I got to go pick up the missus, I found a better schem, I don't think its completely fried, with a few more tests we'll nail it ok RG,, don't worrie.

Later. Rusty.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 10, 2019, 10:31:46 AM
tried posting another schematic for you and pcb layout but it wouldn't met me.

Would I have smelt something had the unit fried?
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rnolan on March 10, 2019, 10:09:39 PM
Hey RG, you need to keep the attachment under 1.5 MB or they don't work.  Dante was looking into it with our ISP to try to get it fixed.  So far the fixes applied haven't worked  :facepalm: .  Hard to think how changing one tube has fried the unit, more likely something was close to going and then did, but as Rusty said, don't jump to conclusions.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: MarshallJMP on March 11, 2019, 06:40:31 AM
Hey RG

You checked all 4 fuses?

Can you send me a pic of the inside of the peavy, maybe I can give you a few testpoints to check?
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 11, 2019, 07:35:28 AM
Ok man I will send a few pics later.

I did check all the fuses.  I took them all out and tested.   They all give me a reading.  I take it they would not register anything if they were blown right?
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 11, 2019, 11:17:15 AM
Ok RG lets give this a try,

Normally in the electronics repair game I use the divide and conquer approach at any point, at anywhere in the circuit and continually do so throughout the process of investigation, this approach provides the fastest analysis when applied, your gonna have to slug it out here with us here so here we go.

Please see the new attachment I have posted. We shall start fron the power side first ok, then we'll move on, be very careful as we are working on live voltage.

First of all, Pull out 12ax7 V4 from the socket.

Secondly, attach your black multimeter probe to chassis ground/earth somewhere and make sure its secure, now you are only using the red probe for safety.

Test 1. Set your multimeter to the highest AC range, usually 500/600V AC on your meter depending on what make it is. (You may have Auto range function built in to your meter, but still make sure your on AC).

With the amp turned on and everything turned down to zero, test the voltage on the F1 fuse, any side will do and tell me what you read.

Test 2. Set your multimeter to the highest DC range, away up as high as it goes (or else Autorange DC), again, it should be 500/600VDC. Now measure the voltages on pin 1 of the V4 socket. (Looking at the socket from the rear side we count the pins in the normal clockwise direction otherwise from the top side where we push the valve in we count in the counter/anti clockwise direction). So tell us what DC voltage you get on pin 1.

Test 3. Set your meter to a lower DC range and tell me what you get on pins 4 and 5, (they are not drawn in on the schem, but you know the deal how to do it now) normally you should see about 12.6 V on either one of those pins with the valve pulled out.

Tell me what you get for test 1, 2 and 3.

It shouldn't take long at all, and from there I'll tell you what to do ok.

Rusty.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 11, 2019, 02:02:12 PM
(https://i.ibb.co/y8yyyFG/IMG-20190311-192803.jpg) (https://ibb.co/y8yyyFG) (https://i.ibb.co/0j4Kj6G/IMG-20190311-192819.jpg) (https://ibb.co/0j4Kj6G) (https://i.ibb.co/4Vd0QZW/IMG-20190311-192906.jpg) (https://ibb.co/4Vd0QZW)

Here are some pics MJMP.

Ok Rusty I may not get the tests done tonight but definitely tomorrow.  I may get them done this evening, if I do I will post later my findings!  Thanks for the help  :thumb-up:
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 11, 2019, 03:28:52 PM
I did what I think was Test 1 and Test 2

I got no reading at all. 

I found pin one using this diagram

http://guitarkitbuilder.com/wp-content/uploads/2013/05/12ax7-base-pinout.jpg (http://guitarkitbuilder.com/wp-content/uploads/2013/05/12ax7-base-pinout.jpg)

I can't remember which way the switch is mean to be in the on position so each measurement I did with the power switch in either position.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 11, 2019, 04:04:38 PM
Right, Nice one, now we got pics,  :thumb-up:

Yes,

http://guitarkitbuilder.com/wp-content/uploads/2013/05/12ax7-base-pinout.jpg

thats looking at the valve base fron the rear side, not the side you plug in your valve. Pin 1 or 6 should be almost the same voltage give or take.

Anyways, try this instead now that we got some pics.

1, Unplug the pre-amp from the wall,
2, Take out both those two plugs that are connected to the PCB from the power transformer.
3, Set your meter to the highest AC range and pop the probes into the two red pins of the white molex connector plug.
4, plug in and power up the preamp and test for voltage there, it should be around from about 150 to about 220 VAC. tell us what you got?

NEXT

5, turn your preamp power off again at the wall.
6, Keep your multimeter on AC, now plug the black probe of your meter into the middle orange wire pin of the other white molex plug with the three orange wires, plug your RED meter probe into the outer orange pins one at a time with the mains power switched back on, tell us what you get ?

Be careful now !!!!!


Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Kim on March 11, 2019, 04:13:46 PM
Damn, that's a bummer RG.  :'(

You gotta love the Peavey stuff like this.  Tough as a tank, simple design and layout, neat and easy to work on should the need ever arise.  My Classic 60/60 tube poweramp (and many other US built Peavey stuff) is another example of "gee whiz, that's all there is inside that awesome sounding and heavy thing?"

Now just find out where the electricity stops flowing.   Carefully!
Start with the mains cord; electricity coming into the chassis?
Juice going into the transformer?
Juice coming out of transformer?
Then follow the circuits from the transformer to the caps.  Juice in?  Juice out?
Etc.  until you find where the electric flow stops.  Again, do this carefully as to not touch stuff with your hands.  Your 230v mains would probably light you right up.   :banana-trip:
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 11, 2019, 04:24:04 PM
Right, Nice one, now we got pics,  :thumb-up:

Yes,

http://guitarkitbuilder.com/wp-content/uploads/2013/05/12ax7-base-pinout.jpg

thats looking at the valve base fron the rear side, not the side you plug in your valve. Pin 1 or 6 should be almost the same voltage give or take.

Anyways, try this instead now that we got some pics.

1, Unplug the pre-amp from the wall,
2, Take out both those two plugs that are connected to the PCB from the power transformer.
3, Set your meter to the highest AC range and pop the probes into the two red pins of the white molex connector plug.
4, plug in and power up the preamp and test for voltage there, it should be around from about 150 to about 220 VAC. tell us what you got?

NEXT

5, turn your preamp power off again at the wall.
6, Keep your multimeter on AC, now plug the black probe of your meter into the middle orange wire pin of the other white molex plug with the three orange wires, plug your RED meter probe into the outer orange pins one at a time with the mains power switched back on, tell us what you get ?

Be careful now !!!!!



So I'm testing the two red wires+white plug that's coming out of the transformer first Rusty?



Hey Kim, yeah gutted man, dunno what happened!  Was on one minute then dead the next!  It is nearly 30 years old I guess, so who know what might have failed on it.  I tested voltage going into the power chord and it's definitely reaching the tranny.  That's all I know for sure right now.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 11, 2019, 04:35:30 PM
Yes, we are testing the two red wires on the white plug that comes from the transformer. AC voltage.

Also, we are testing the middle orange with the two outer orange wires seperately, the middle orange wire being zero volts (floating now), each outer orange wire on the plug should have AC also,  check the two outer orange wires together and the voltage should be double.

Careful man !!! 
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 11, 2019, 04:45:24 PM
ok I did that on both plugs.

First plug with red wires, put the two prongs into the either hole where each of the red wires goes to.  Got nothing.

Next did the orange wired plug, put the black in the middles and used the red prong in either of the other holes side by side of the centre.  Nothing on the meter!

Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 11, 2019, 04:47:24 PM
Ok hitting the sack here, I'll pick this up tomorrow, thanks again for helping.  I just tried those tests again and still nothing.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 11, 2019, 04:58:04 PM
OK, tomorrow we'll test the primary (otherside) of the transformer tomorrow and everything else on the live mains side with those two plugs pulled out.
 
We'll be working on mains 240VAC next,  if you have a GFCI or RCD outlet adaptor knocking about that would come in handy for safety.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: MarshallJMP on March 11, 2019, 05:10:58 PM
Let's start simple and safe, set your meter to ohms, UNPLUG the peavy, set the power switch to on and measure on the power plug, you should have resistance (in the 50-100 ohm range I guess) then unplug the red and orange plug, red plug measure the resistance between the 2 connections, orange measure the resistance of the 2 outer connections and then the middle to left and middle to right. Let us know. If this checks out you know the transformer is good.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 11, 2019, 06:59:37 PM
ok I did that on both plugs.

First plug with red wires, put the two prongs into the either hole where each of the red wires goes to.  Got nothing.

Next did the orange wired plug, put the black in the middles and used the red prong in either of the other holes side by side of the centre.  Nothing on the meter!


Right, we are almost there RG,  Take your time and be safe  !!!

With those two plugs still un-plugged out from the PCB and with your meter on the highest AC range and the mains switched on.

Connect the black probe of your meter to the white wire on the rear voltage selector beside the incoming blue neutral wire then test both of those black wire solder connections on the front rocker switch, flip the switch if need be, you got to be reading 240VAC on both of those black wires on the switch.

If so, with the power still on, go back and test the two red wires again on that plug disconnected from the PCB, any way around with your meter probes will do.

Also, with the power still on, test the orange wires as before, with the plug disconnected from the PCB, the black meter probe to the middle orange wire and the red meter probe to the outer orange wires seperately and tell us what you got ?

Here's a drawing that may help you understand more clearly what I mean, sorry if its a little bit rough and ready  :)


          *** Edit ***More info ***

Hey RG I found this on https://music-electronics-forum.com/showthread.php?t=47870

It looks about right to me for the secondary output voltages of what that transformer should be around.

The secondary specs for the 70529303 are:
Sec 1 322 vac @ .041 amps
Sec 2 41.9 vac CT @ .403

Meaning; the voltage across the two reds should be about, 322 VAC

and the voltage across the two outer oranges about, 42 VAC
and with the orange center tap in the middle,  21 - 0.4 - 21 VAC

My hand drawn voltage values were only a guestimate on the drawing attachment,  :)


Hope thats of any help,  Let us know what you get.

Take your time, don't panic and be safe !!!!   :)



 
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 12, 2019, 10:37:45 AM

Connect the black probe of your meter to the white wire on the rear voltage selector beside the incoming blue neutral wire then test both of those black wire solder connections on the front rocker switch, flip the switch if need be, you got to be reading 240VAC on both of those black wires on the switch.

Ok I did this and I only get a reading on the lower black wire for about 235v.  Does this mean the power switch has failed and the cause of the issue??
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 12, 2019, 11:01:23 AM
It could be RG. hopefully it is, BUT do this test first.

1,  Unplug the pre-amp from the wall socket
2,  Set your meter to the lowest ohms range, usually 200 ohms (again you might have auto range so don't worrie)
3,  put your probes upon those two black wires on the rocker switch and switch it on and off,

your meter should read from 000.00 ohms and then change to 20 million ohms (normally indicated by just a 1 on your meter display = infinity) as you flip the switch on and off.

If the reading doesn't change on the meter when you switch and your ohms reading is always a 1 then the switch has packed up !

lettuce no what you get ?

Good man.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 12, 2019, 11:03:21 AM
Also I tested connectivity with the power switch and at no point do the two terminals allow for connectivity.  Suggesting to me the switch has gone (which makes sense as it has been switched on and off a lot since I have been tube rolling).  Any way of testing to be sure?
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 12, 2019, 11:05:29 AM
try my ohms test above first please RG,
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 12, 2019, 11:08:50 AM
Just did the test again using the ohm setting, when the two leads touch, I get a reading fluctuating from 01.0 to 00.05.

When I place the leads on the two terminals of the switch and flick it on and off I get nothing in either setting!

my meter defaults to "1" when there is no reading.  When it receives  a reading at this setting it changes to 00.0 and then will move up or down depending on the reading.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 12, 2019, 11:21:36 AM
UNPLUGGED of course !!!!!


Make sure you have a clean contact with your meter probes on those solder joints of both black wires, scape off the old solder residue rosin on those wire joints with a knife or something like that first so you get good clean contact with you meter probes.

Then place your meter probes across each solder wire joint and turn the switch on and off, your meter should respond accordinly,  we are not looking for exact meter readins here, as long as we see 1 or zero ish alternating on and off that should be good enough on the meter to show.

if not then the switch has packed it's bags.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 12, 2019, 11:31:15 AM
Ok here are pics, first pic meter with out probes touching
(https://i.ibb.co/vVN1jzs/IMG-20190312-181630.jpg) (https://ibb.co/vVN1jzs)

second is what I get when the leads touch

(https://i.ibb.co/vPpV4n6/IMG-20190312-181650.jpg) (https://ibb.co/vPpV4n6)

third leads touching the switch terminals and the rocker in the down position

(https://i.ibb.co/Dr7LDML/IMG-20190312-181818.jpg) (https://ibb.co/Dr7LDML)

fourth leads touching the switch terminals and the rocker in the up position

(https://i.ibb.co/myRLYcC/IMG-20190312-181827.jpg) (https://ibb.co/myRLYcC)
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 12, 2019, 11:34:54 AM
The switch is f*cked RG

Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 12, 2019, 11:37:20 AM
Occasionally when the leads would slip and the metal probes would make contact with one another I would get a reading, but when they were 100% separated from each other bar the terminals in the switch I still got no reading. 

  :???:  Is it safe to say its the switch? :???:

If the switch is knackered, this is a good thing right?  Minimal hassle replacing considering what could been right?

this switch appears to be the right size of chassis,  would it be suitable?

https://www.ebay.co.uk/itm/18mm-X-11mm-SPST-Small-Rectangular-Rocker-Switch-Black-White-2-Pin-ON-OFF-250V/123168302435?hash=item1cad672563:m:mYjj2BWUSQVETfoXT9p4_3g (https://www.ebay.co.uk/itm/18mm-X-11mm-SPST-Small-Rectangular-Rocker-Switch-Black-White-2-Pin-ON-OFF-250V/123168302435?hash=item1cad672563:m:mYjj2BWUSQVETfoXT9p4_3g)

**edit**  it's not the right size actually, I need 20mm x 15mm
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 12, 2019, 11:50:07 AM
Try this RG but be very careful ok !!!!!!

1,  Snip the two black wires off the rocker switch and strip them both off to the copper and twist them together carefully so they don't come apart.

2,  with the two PCB plugs still UN-PLUGGED from the PCB board plug the pre-amp back into the mains outlet

3,  Set your meter back to the highest AC voltage range and probe the orange wires first as we said before.  sling your meter probes into the two outer orange wire pins of the plug, not the socket.

4,  Sling your meter probes into the two red wire plug also, anyway around on this plug will do and lettuce no what you get,,,


As I said before,  be patient, don't panic and be safe,  !!!!!!
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 12, 2019, 12:53:50 PM
Ok didn't snip the wires, just unsoldered them and then hard wired them together.

Tested the orange plug first, black in the centre pin then a measurement using the red from each of the side pins.

I got 20v on either side pin.

On the red cable with probes touching both pins I got 335v

I just realised I did one of the tests wrong, I didn't switch the meter to dc whilst measuring the orange wired plug.

Also I didn't have valve 4 removed.  Should I try it again?

I did test the unit turning on and it switched on no problem so I'm hoping everything is ok and all I need is a new switch.

***edit*** went back and re-read all your posts, no I did the tests right and I got pretty close to the numbers that you got from that website.

You said 322v for the red wired plug, I got 335v 

you said 21 04 21 for the orange wired cable, I got 20 for each side wire.  Never measured the middle.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 12, 2019, 01:00:49 PM
Yip RG,   

I have seen that whole thing happen before on other electronic equiment.

You know what to do next , OK

Your good to go sir,

Rusty,   :thumb-up:
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 12, 2019, 01:05:04 PM
edited my last post just in case you didn't read it.

Thanks for helping me there.  Kind scary dealing with all those volts.  Actually cannot believe I can get the unit fixed now by changing the switch.  I plan on modding this preamp further than I already have BTW.  I changed two resistors to allow for higher plate voltage and one cap on the tube board to allow more low end through.  I shall replace another few caps to allow more low end though.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 14, 2019, 04:05:02 AM
Been playing the Rockmaster again last night.  Hard wired the two power switch wires together and then put some tape around them until my new switch arrives.  I think I have bough a switch suitable.  Said 6A at 250v 10A at 125v.  The original just said (in the smallest type/text I have ever seen) 10A 250v 125v.  Will this be ok?

Rusty I should be ok for the Rockmaster mods.  I've read conflicting things though about some of them, namely the mods that deal with changing caps to allow more bottom end though.  It may be trial and error as the guy I got the information from carried out the mods on one forum but on another forum said it made things worse for him......but then later confessed that his rockmaster may have had a problem so whether the mods are worth it I dunno.  Basically I would like it a little thicker sounding for a start anyway.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 15, 2019, 01:55:53 AM
Been playing the Rockmaster again last night.  Hard wired the two power switch wires together and then put some tape around them until my new switch arrives.  I think I have bough a switch suitable.  Said 6A at 250v 10A at 125v.  The original just said (in the smallest type/text I have ever seen) 10A 250v 125v.  Will this be ok?

Rusty I should be ok for the Rockmaster mods.  I've read conflicting things though about some of them, namely the mods that deal with changing caps to allow more bottom end though.  It may be trial and error as the guy I got the information from carried out the mods on one forum but on another forum said it made things worse for him......but then later confessed that his rockmaster may have had a problem so whether the mods are worth it I dunno.  Basically I would like it a little thicker sounding for a start anyway.

Hey RG,
That switch you ordered is fine and well within spec, you may just have to file the metal chassis a little to make it fit from USA imperial to metric I'm guessing.

As far as those mods go, yes, normally playing around with the tone stack resistors and capacitors normally yields lots of options for variations of over tone adjustments. So does changing the interstage AC coupling capacitors and V1A input capacitor's C1 and C2 and R105 for example. There are many ways to thicken the tone, It's a matter of me studying the best way to go about it I suppose. I could give you some advice mabye.

Another way is to load up with decent quality valves. Good quality NOS if you can afford them, at least one or maybe two at V1 and V2, definitely V1 though, expect to pay about £40-£50 bucks each. Be aware first, you are getting into the tube rollers club which is a highly subjective subject.

Thats just another option you can consider before getting the solder welder out.

Keep me posted, Rusty.


   **** Edit, Just saw this ****

I changed two resistors to allow for higher plate voltage and one cap on the tube board to allow more low end through.  I shall replace another few caps to allow more low end though.

Which resistors did you change and what cap did you change RG ?,  Let's keep track of what you have done and what has previously been done. Raising the plate voltage will automatically change the original Rockmaster design biasing of the valve.
 
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 15, 2019, 03:02:07 AM
No sweat man, I'll let you know when the switch arrives.  Discovered a new and useful mod!!  And I tested it last night albeit temporarily.  But by gum it works!!  Perhaps we should start a new thread?  I dunno?  Is it appropriate an ADA forum????

***EDIT***

Depending on the new thread for this idea, I will let you know what has been done so far.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: Rusty on March 15, 2019, 03:55:14 AM
No sweat man, I'll let you know when the switch arrives.  Discovered a new and useful mod!!  And I tested it last night albeit temporarily.  But by gum it works!!  Perhaps we should start a new thread?  I dunno?  Is it appropriate an ADA forum????

***EDIT***

Depending on the new thread for this idea, I will let you know what has been done so far.

Yes a new thread would be a good idea. Here in the Non ADA Gear > Rack gear department and tell me what that new mod is and all the other changes too.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on March 30, 2019, 04:16:47 AM
Some photos of the new switch replacement.

(https://i.ibb.co/5TP02Hs/IMG-20190319-181855.jpg) (https://ibb.co/5TP02Hs)

(https://i.ibb.co/BVVzZ90/IMG-20190319-182255.jpg) (https://ibb.co/BVVzZ90)

(https://i.ibb.co/q7FWs30/IMG-20190322-202929.jpg) (https://ibb.co/q7FWs30)

(https://i.ibb.co/rcXC8MH/IMG-20190322-202957.jpg) (https://ibb.co/rcXC8MH)

(https://i.ibb.co/G7dq1tc/IMG-20190322-204024.jpg) (https://ibb.co/G7dq1tc)

(https://i.ibb.co/d63ZXtf/IMG-20190322-204724.jpg) (https://ibb.co/d63ZXtf)

(https://i.ibb.co/LhnBQt7/IMG-20190322-204740.jpg) (https://ibb.co/LhnBQt7)

(https://i.ibb.co/L8fs9J2/IMG-20190322-210247.jpg) (https://ibb.co/L8fs9J2)

(https://i.ibb.co/8mwDmpC/IMG-20190322-210316.jpg) (https://ibb.co/8mwDmpC)

(https://i.ibb.co/qpwhcY1/IMG-20190322-210326.jpg) (https://ibb.co/qpwhcY1)

(https://i.ibb.co/WzzZp0Y/IMG-20190322-210908.jpg) (https://ibb.co/WzzZp0Y)

(https://i.ibb.co/0yq71kx/IMG-20190322-212120-1.jpg) (https://ibb.co/0yq71kx)

(https://i.ibb.co/n7dH120/IMG-20190322-212521.jpg) (https://ibb.co/n7dH120)

(https://i.ibb.co/Lp1Fj6Z/IMG-20190322-212531.jpg) (https://ibb.co/Lp1Fj6Z)

(https://i.ibb.co/WPjQhVB/IMG-20190322-214039.jpg) (https://ibb.co/WPjQhVB)

(https://i.ibb.co/ZSn2JL7/IMG-20190322-214141.jpg) (https://ibb.co/ZSn2JL7)
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rnolan on March 31, 2019, 11:56:12 PM
Hey RG, very cool  :thumb-up: , so all is good now ? you can be the master of rock again LoL.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on April 03, 2019, 03:17:14 PM
Yes all is good.

Now it's time for some modding!!

A major amazing development has also taken place.  Some JJ Cryogenic tubes that I originally got inside when I bought my 3TM turned out to be the perfect tubes for the Rockmaster.  The touch sensitivity is amazing.  The perfect feel for me, like liquid.  And the tone is excellent as well.  Funny I thought those tubes where shit, I've not had much luck with JJ's and I have been rolling a lot of tubes in and out of that Rockmaster recently (which is how broke the switch in the first place).

So now I know to buy those tubes again from Watford valves (who sell them).  Lets see though if we can get a little more low end into the Rockmaster with a few mods.  Those tubes also improved the low end as well.  Probably the right amount for recording with to be honest.
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rnolan on April 03, 2019, 10:57:59 PM
It's amazing how much difference the right tubes make, I had similar results with the Mullard LPs in my MP2, just a perfect fit in that circuit.  Good you tripped over that  :thumb-up: :whoohoo!:
Title: Re: Peavey Rockmaster - possibly blown to death!!
Post by: rabidgerry on April 05, 2019, 01:27:38 PM
I don't buy the "cryogenic" sh :poop:t at all, but all I know these tubes sound great in this preamp.

Another good discovery (and all I ever hear is about the over hype regarding these) is a couple of Groove Tubes I had lying about from another MP1 that came with them in.  These are a close second to the JJ Cryo's in the rockmaster.  Different kind of tone though but the touch sensitivity is there.  Haven't tried a combination using both.  I may do at some point.  Using both those tubes I just have cheap Bugera tubes in v3 and v4.