Build a lower wattage "2204"?

[guitarmv]

I finally have my 4010 up and running, and it is way too loud for the gigs I do. The tone is undeniable, with the master volume barely hitting 2, but I had been using my Peavey Classic 50 which sounds great, and pegs out just about at top club volume.

I intend to rebuild this amp anyway, but I dont know (yet) how I could go about getting this kind of tone out of a lower wattage setup. I've seen some Jubilees had 25/50w switching, but I am thinking 35-40 watts (are these hopelessly idiotic numbers?) would likely be appropriate levels for my needs.

It would appear that attenuators, pedals and soaks, are a bad idea?

And you know what kind of sucks - I have too learn to work all these formulas, but I was a total burnout in school (ah the 70s), and the electronics math makes my head hurt. But I am getting into this so much that...I am willing to......I will try to.....I am going to have to figure this g&^^%#m stuff out.

But, man, this tone - where the hell have I been all these years? ABM, Anything But Marshall, but I couldn't tell you why. Now I obsess.

[gldtp99]

Why don't you try a pair of JJ 6V6S output tubes in the 4010----- they are rated 500V on plates and 450V on screens, much hardier than typical NOS-type 6V6's----you might want to double the output load (amp impedance switch on 8 ohms into a 16 ohm speaker, for instance). Also get an ineffecient speaker---these two moves (JJ 6V6S output tubes and different speaker) would probably allow the amp to run in the Vol range you need---no need to rebuild the amp.
I've built 25 watt and 14/7 (switchable) watt amps with 2204 preamps and a 35 watt "hotrodded plexi" ----- the 25 watter runs JJ 6V6S and Heyboer 18 watt Marshall iron with ss rec (no tube rec) and is fixed bias----- the 14/7 runs a pair of EL84's and is cathode biased, a pentode/triode switch adjusts power level on this one, the same as the Jube's------ the 35 watter uses 7868 output tubes and was used as a stage amp (a couple of yrs) until my friend got into a very loud band and needed a 4x12 pushed by big wattage, so i built him a 75 watt version and it's seemed to be enough.
Lower wattage 2204-type amps are possible but don't butcher up your 4010 chassis to make one----- just go to lower speaker effeciency and run JJ 6V6S output tubes with the amp you already have.........................gldtp99

[phsyconoodler]

You've got the amp already.Why not look into Variable voltage regulation?
It would turn that amp into a very useable and satisfying small club amp.
Or you could add a post phase inverter master volume on top of the existing master to get some lower volume sweetness.
Not literally 'on top'. but as well as.

[BCJek]

I agree with gldtp99 - try the jj's. Quick way to drop a few watts without mods. I have a 2204-style preamp in an amp with switchable outputs. I put a pair of JJ6V6 in one pair of sockets for lower wattage than the other pair [6L6 or EL34].

[guitarmv]

I've actually got a set of "Fender" EH 6V6GT's sitting here from a GAS impulse purchase a few months back, cool beans!

I put the Vintage 30 Dr Z duet in the amp, man I would hate to taken em out.......maybe I could put them in the VHT cab I have. Next week I will receive my 50/100 Black Jubilee, would these tubes also work in that little puppy?

I like the idea of the switchable outputs, but I hear ya about not chopping the 4010.

Now I get to try biasing.

[guitarmv]

While I have your attention, I ordered new caps for the 2204, and for bias caps he sent me 2 100uF 100v, which are different from what is in there. Are these acceptable subs?

[gldtp99]

The proper bias caps are 10uF/100V-----get some and put them in----- we've suggested using JJ 6V6S output tubes because they are rated to handle the voltages in the amp----- i have no idea if the EH 6V6 tubes are rated to handle these voltages----i wouldn't use the EH's in this application without knowing their ratings.
For a positive outcome, use the right parts.
Also, using the JJ 6V6S tubes may require some modification to the bias circuit to enable biasing these 6V6-type tubes in the proper range---- if you don't know how to do this then please take the amp to a tech who can..........gldtp99

[HipKitty]

You've got the amp already.Why not look into Variable voltage regulation?
It would turn that amp into a very useable and satisfying small club amp.
Or you could add a post phase inverter master volume on top of the existing master to get some lower volume sweetness.
Not literally 'on top'. but as well as.

+1,000!

I wouldn't use the EH 6V6's in there...as far as the JJ 6V6's, they aren't a true 6V6, which is why they can handle the higher voltages...kinda a cross between a 6L6 and a 6V6 to make it better understood. Even if you were to do the 6V6 approach, it really wouldn't drop down the volume to a (more) acceptable level, not as much as a PPIMV or VVR.

[guitarmv]

gldtp99 - I appreciate the advice and concern, I am in the process of learning to become an amp tech myself, and luckily have my own equipment, like this Marshall, an AB165 SF Bassman 50, Peavey Classic 50, Epi Valve Jr, to learn on, well before I deign to tackle amp issues for someone else. Being an on-call computer tech contractor for a high-end systems provider, I have the time and wherewithal to devote to this. Believe me, I am eating living and breathing this stuff practically 24/7, vids, books, articles, TGP, and getting inside my amps, guitars, and effects pedals. I've been a performer for 30 years, and decided, at 49, that this is the appropriate next step.

Which means I also have to learn electronics, and that mostly takes place in the "library", if you know what I mean.

AND I drain my caps each and every time! I live at my bench, and ignore the rest of my place now (bench, library - if you know what I mean, work, when it gets in the way, and bed).

I am looking up the PPIMV/VVR approach, and am ordering the correct caps for biasing. I dont know why I was sent these, but now I have them for something else. I am working on how to bias with a dmm, going to build a tube socket bias meter, and have an oscilloscope that sits there like an alien, but I WILL figure it out.

I can and will look this up, but what is the probable outcome/damage that would come from using the EH 6V6's?

Thanks for all the help and advice, truly appreciated!

[edit] Obviously, I am single, hence to hell with everything else not ampish.

[phsyconoodler]

Quote: " Obviously, I am single, hence to hell with everything else not ampish."

Me too and some guys who work on amps will be single soon too if they spend as much time as we do.:agree

Easy way to measure power tube current:with the amp off,taske your ohmmeter and measure the reesistance from the power tube plate(pin 3) to the OT centre tap.Record that for each tube.Now fire the amp up and measure the DC voltage at the same points.Divide the voltage by the ohms to get the current.
i.e. say you get 430 ohms and 1.4vDC. 1.4/430=.00325 or 32ma
Accurate,easy and no transformer shunting going on here.
Thanks to hasserl for this one.

[mmorse]

The proper bias caps are 10uF/100V-----get some and put them in----- we've suggested using JJ 6V6S output tubes because they are rated to handle the voltages in the amp----- i have no idea if the EH 6V6 tubes are rated to handle these voltages----i wouldn't use the EH's in this application without knowing their ratings.
For a positive outcome, use the right parts.
Also, using the JJ 6V6S tubes may require some modification to the bias circuit to enable biasing these 6V6-type tubes in the proper range---- if you don't know how to do this then please take the amp to a tech who can..........gldtp99

I did this with my 2204. I used the JJs. Cut the wattage down to 22 watts without loss of tone. Sounded nearly as good as when I had a pair of old Mullard XF2s in it. Headroom suffered a bit though. Had to change the bias resistor to get them to bias properly. Also did the impedance thing. It dropped the volume but not a whole lot.

[guitarmv]

What's "quickly"? I have been noticing sag in the amp as is, at louder volumes, low end power chords, if I have sussed sag correctly. It is a compression effect, and last about an 1/8 - 1/4 beat at 140bpm or so.

[guitarmv]

we've suggested using JJ 6V6S output tubes because they are rated to handle the voltages in the amp

Am I looking for Limiting Values, or Typical Characteristics (Ua=, etc) to compare the 2, and what should I look for in the differences, similarities.

Thanks

[Edit] I'm getting there, I'm getting there - on the spec sheet I am looking at (JJ6V6s) the ratings obviously correspond with pins per the nomenclature, where I can see the plate, grid, heater. I am curious why this this has two specs, triode and pentode. I see the single-tube (class a, right?) and push-pull, (class A/B?) ratings are evident, do these correspond with triode/pentode, per usage?

Also also, the 6V6GT is listed as a substitute, not sure if that bears any weight, and I can not find a ratings sheet for that tube.

[guitarmv]

AND would removing one of the speakers result in lower output?

[phsyconoodler]

With 6V6's you need to DOUBLE the speaker load.So if you have 4 ohms now,you need 8 ohms load.
Marshall's have impedance selectors that make life easier here.

[gldtp99]

OK, something doesn't add up here--- a 4010 is a 50 watt 1x12 JCM 800 combo---- it has one 12" speaker (i have a 4010 sitting here)---- you must have a 2x12 combo with a 4010 chassis installed----- the 4104 was the 2x12 50 watt JCM 800 combo.
See Dr Tube: http://www.drtube.com/marshall.htm#JCM800

So, anyway---- if you have two speakers, of course using only one will give less volume.
If the EH 6V6's fail because they aren't rated for the loads imposed--- other amp components could possibly be damaged--- possibly screen grid resistors, OT, or other----- maybe or maybe not----- i'd use JJ 6V6S output tubes and not have to worry about it and save the EH's for another amp---- why set up an amp with a possible weak point ? Failures seem to come at the worst possible time (some law by Murphy or somebody)..................gldtp99

[phsyconoodler]

Yes,using a speaker with less sensitivity will DEFINITELY give less volume.
Many 1-12 50 watt marshall's with the G12M70 were quite quiet.