JCM800 - Bedroom level playing - Any hope?

[Richman1]

Get the Groove tubes EL34 to EL84 conversion sockets...that takes the amp down to 18 watts...they cost 100 bucks and work great for the bedroom...easy to install...no tech needed...self bias..just stick them in and play...I have a DSL50 set up like that through a greenback cab...sounds killer in the bedroom....

 

[Lespaulnmarshall]

Well 800's are loud dude, but Fender HRD's too... I can play my VM at 7 or 8 at home without disturbing but that hurts my ears, and over 10 years I can't even hear a cranked plexi anymore ! So get a good attenuator and run it around -10db, set your amp at 5 or so and rock out with a tube screamer (as a clean boost) your guitar and your 800. I use a 2x12 cab with my VM, the cab has V30's and a closed back and is made out ou verry thick wood, sonds KILLER ! A 2X12 will make it less loud and still awsome (and thick) too !

 

[Purgasound]

I play my 800 at bedroom levels easy. It is a halfstack and I can get great little tones playing in my bedroom. I can manage it and I like the sounds I get when it is queit. I have never quite gotten the concept of an amp not being able to be played at bedroom levels providing they have a MV.

+1

If you've got to make the amp whisper then you're better off with headphones and a Little Smokey amp. No sympathy for MITLS.

 

[Purgasound]

Forgive me because I don't know but does this amp have an effects loop?

2204, 2203, 1987, 1959 - No

2210, 2205, 2203RI - Yes

 

[butrus]

I have exelent results with THD Hot Plate set to load,and line out signal into Velocity 150(solid state power amp) into 2x12
Much better sound then using yust HP.
This way I can have volume on my JCM800 on 8 and sound great at bedroom volume

 

[MartyStrat54]

Get the Groove tubes EL34 to EL84 conversion sockets...that takes the amp down to 18 watts...they cost 100 bucks and work great for the bedroom...easy to install...no tech needed...self bias..just stick them in and play...I have a DSL50 set up like that through a greenback cab...sounds killer in the bedroom....

How long they been in there and what amount of playing time? One of my buddies did a thread on these and at first he thought they were great, but then they failed. One actually burned up the EL84. The electronics are encapsulated in the base and the big power resistor get so hot it actually bulges out of the base.

He sent the first one back and then the replacement and the other one did the same thing. He returned everything and got his money back. Needless to say, he was not happy about the outcome.

If they are working for you that's great.

 

[MartyStrat54]

Any 50 Watt and lower tube amp can use a module that scales the power back to the power tubes and keeps the tone.

It's called Power Scaling..... SkipZ's VariWatt.... Home


There are many others out there that do the same thing too....

Have you personally put one of these together and used it, or are you stating it is a good product without actually using it?

These are kits and some guys can't do these. One model is for cathode biased amps only and the one for a 50 watt 800 requires the user to build two modules. It doesn't even show a case for the modules. Maybe I didn't see it, but it wasn't listed when they showed the prices.

There are a lot of various "volume controls" that hook up in the FX loop. These are redundant and make no difference especially on a MV amp. In other words, they are pretty much junk, or everyone on the forum would be using them. There was a thread on these units and the majority stated they were junk, but what do you expect for $29.99?

If you built the dual module unit, would you please write up a report on it so the members can determine whether this is something they would like to try.

 

[pinto79]

I use both my 2203 and my 6100 at low to moderate volume without an attenuator. The 1959RR is another story...

I find that either of them work well with an EQ in to loop (I modded the 2203) and an OD in front.

 

[DC135er]

Instead of spending all that money on attenuators and brakes and stuff, why don't you just break down and get the Marshall Haze?

 

[Azaril000]

Isnt that supposed to be just as loud or near enough anyway?

 

[jcmjmp]

Have you personally put one of these together and used it, or are you stating it is a good product without actually using it?

These are kits and some guys can't do these. One model is for cathode biased amps only and the one for a 50 watt 800 requires the user to build two modules. It doesn't even show a case for the modules. Maybe I didn't see it, but it wasn't listed when they showed the prices.

There are a lot of various "volume controls" that hook up in the FX loop. These are redundant and make no difference especially on a MV amp. In other words, they are pretty much junk, or everyone on the forum would be using them. There was a thread on these units and the majority stated they were junk, but what do you expect for $29.99?

If you built the dual module unit, would you please write up a report on it so the members can determine whether this is something they would like to try.

The Skipz vari watt is an excellent tool to control the output power of your amp and works very well. Many have installed it and it works very well. This is not a volume control.

MetroAmp.com Forum • View topic - Power Scaling mod

 

[MartyStrat54]

The Skipz vari watt is an excellent tool to control the output power of your amp and works very well. Many have installed it and it works very well. This is not a volume control.

MetroAmp.com Forum • View topic - Power Scaling mod

Thanks JCMJMP-I hadn't heard of these before (lots of stuff out there). How are they connected to the amp? The parts breakdown looks like it has two huge power soaking resistors as part of the circuit. Does it alter the high end of the amp? How do they sound compared to a quality attenuator? I might be interested in building one of these.

 

[jcmjmp]

Thanks JCMJMP-I hadn't heard of these before (lots of stuff out there). How are they connected to the amp? The parts breakdown looks like it has two huge power soaking resistors as part of the circuit. Does it alter the high end of the amp? How do they sound compared to a quality attenuator? I might be interested in building one of these.

I don't have this in my amp (JTM45 Clone) but will install one when I build my Metro JTM45. I have instructions on how to install the power scaler and its actually quite intuitive. The resistors aren't really for power soaking though. This mod controls the B+ voltage going to the tubes and tracks the bias accordingly.

 

[Purgasound]

I don't have this in my amp (JTM45 Clone) but will install one when I build my Metro JTM45. I have instructions on how to install the power scaler and its actually quite intuitive. The resistors aren't really for power soaking though. This mod controls the B+ voltage going to the tubes and tracks the bias accordingly.

I've been reading up on this out of curiosity generated by this thread but still amp trying to figure out how this thing works.

Is it actually lowering the current flow to the output section of the tubes? This is mainly what I'm trying to figure out. Is it actually lowering the plate voltage going to the tubes and if so how can it adjust the bias accordingly? Also if that's how it is, is that safe for the output transformer. I've heard horror stories about Variacs and EVH wannabes who get sad real quick.

 

[Azaril000]

Just a little update, I went for it and bought the JCM 800! It nearly blew my ears off when the guy demo'd it for me at volume 2-3 with a 2x12 cab but actually it sounded really usable at 0.5 volume, and even if i went lower, I can just stick a booster/OD until i buy a attenuator. The only bad thing is I'll need tow ait a bit to buy a cab, so it'll be using the speaker of my HRD.

 

[LPMarshall hack]

Just a little update, I went for it and bought the JCM 800! It nearly blew my ears off when the guy demo'd it for me at volume 2-3 with a 2x12 cab but actually it sounded really usable at 0.5 volume, and even if i went lower, I can just stick a booster/OD until i buy a attenuator. The only bad thing is I'll need tow ait a bit to buy a cab, so it'll be using the speaker of my HRD.

Good choice. That's a great amp. Get yourself a 4x12 cab though. You'll be happier in the long run. Enjoy!

 

[PaoloJM]

I've been reading up on this out of curiosity generated by this thread but still amp trying to figure out how this thing works.

Is it actually lowering the current flow to the output section of the tubes? This is mainly what I'm trying to figure out. Is it actually lowering the plate voltage going to the tubes and if so how can it adjust the bias accordingly? Also if that's how it is, is that safe for the output transformer. I've heard horror stories about Variacs and EVH wannabes who get sad real quick.

It seems to be very like London Powers Power Scaling and VVR.
They essentially do the same thing.
By dropping plate and screen voltage while "tracking" the bias voltage (it eventually goes positive BTW!!) the transfer curves of the valve remains constant and so the valve generates a pretty much constant tone right down to 1/2 watt or so.
Sometime the entire amp is scaled, or sometimes just the power valves and a "drive" control is integrated to control the signal level from the PI when you're scaling down.

You are still missing those three old chestnuts though: lots of air moving, speaker breakup and OT saturation.

Works pretty well from the clips I've heard and doesn't have the disadvantage of reducing the negative feedback (ie. presence and resonance controls will still work), PPIMVs render these controls useless unless you're fully cranked. It also has the advantage of running much easier on your valves.

As I said the clips sound good but I'm not convinced that the hassle factor is worth it versus the PPIMV.

 

[Azaril000]

I have another question! Whats a good "cheap" cab for this amp. I mean I would eventually get a good cab in the future, but for now, any idea's?

Also, how much of a difference is there between 1x12 cabs and 2x12 cabs? Very noticable? Obviously im trying to keep the tone as smooth and awesome as possible, but with smaller setup/room.

Lastly how much of of a mistake would it be to buy those 1x12 cabs for the new Marshal Haze? Marshall Haze MHZ112A 66 Watt Angled 112 Cab:
http://www.nevadamusic.co.uk/Guitar_Amplifiers_and_Speakers/Guitar_Amps,_Combos_and_Cabinets/Guitar_Speaker_Cabinets/sc1587/p7999.aspx?utm_source=google&utm_medium=GoogleShopping&utm_campaign=googlebase&utm_term={keyword}

Would it damage the jcm800 or would the speakers be pushed past its limits? Im not too familiar with the head and cab stuff!

Thanks.

 

[DC135er]

Isnt that supposed to be just as loud or near enough anyway?

The smaller version has 15 watts. If that's still too loud you could try the Marshall class 5 with a whopping 5 watts.

 

[Purgasound]

It seems to be very like London Powers Power Scaling and VVR.
They essentially do the same thing.
By dropping plate and screen voltage while "tracking" the bias voltage (it eventually goes positive BTW!!) the transfer curves of the valve remains constant and so the valve generates a pretty much constant tone right down to 1/2 watt or so.
Sometime the entire amp is scaled, or sometimes just the power valves and a "drive" control is integrated to control the signal level from the PI when you're scaling down.

You are still missing those three old chestnuts though: lots of air moving, speaker breakup and OT saturation.

Works pretty well from the clips I've heard and doesn't have the disadvantage of reducing the negative feedback (ie. presence and resonance controls will still work), PPIMVs render these controls useless unless you're fully cranked. It also has the advantage of running much easier on your valves.

As I said the clips sound good but I'm not convinced that the hassle factor is worth it versus the PPIMV.

What about on an amp that already has master volume? Specifically the 2204. Once those are past 1 they are pretty much wide open. The only thing you get as you turn the volume up is just more power tube saturation. Would it be worth it to put one of those in to control it or would it just be better and easier to take the Audio tapered volume pot out and replace it with a linear one?