Other Amps

Hey amp dudes…..

1

I have a question regarding a new to me amp. Bought a 3Monkeys 18watt non-master amp that has a certain “stiffness” to its sound/attack. What is suggested to soften it up a bit? It has a 3 stage preamp and two el84 power tubes. Running two 10 inch Greenback speakers.

I did a little experiment and ran it with only one 10 and it seemed to soften it up a bit. I’m looking for a more rounded tone. Pretty chord sound (a little more blending of notes).

2

I have a question regarding a new to me amp. Bought a 3Monkeys 18watt non-master amp that has a certain “stiffness” to its sound/attack. What is suggested to soften it up a bit? It has a 3 stage preamp and two el84 power tubes. Running two 10 inch Greenback speakers.

I did a little experiment and ran it with only one 10 and it seemed to soften it up a bit. I’m looking for a more rounded tone. Pretty chord sound (a little more blending of notes).

– Hipbone

What rectifier is it running?

3

It has a Tung-sol 12AX7 In V1 and jj ECC83S for V2 and V3

4

It’s a SS rectifier.

5

I think it utilizes a SS recto. Not much you can do there without surgery. It’s gonna be a stiff amp.

You could try a 12AY7 or 5751 in V1 to lower the preamp gain a little, that way you can push the power tubes a little harder using your MV setup for some sponginess. But with the SS recto you’ve got no sag at all.

6

If there's no recto tube, then it's likely solid state. Still I'd expect 2 x EL84 to be pretty "soft"already. I assume they're cathode biased. Depending how surgical you want to get, there are a few options:

  • Compressor pedal. Sometimes that's all you need.

  • New speakers. Greenbacks are "barky", maybe you'd prefer something "American" voiced, with a hemp cone.

  • Sag Resistor. This is placed in series with your B+ to emulate the resistance of a tube rectifier. As the amp pulls more current (say, during a power chord), proportionally more voltage is dropped across the resistor which feeds your power tubes. It's built-in compression.

  • Higher plate load resistors. This is one of my favorites for increasing the spongy, ragged, in-between-ness of an amp, but it comes at the cost of any crystal cleans. I love a 220k on the preamp triodes.

Without a schematic, it's hard to offer much else.

7

If there's no recto tube, then it's likely solid state. Still I'd expect 2 x EL84 to be pretty "soft"already. I assume they're cathode biased. Depending how surgical you want to get, there are a few options:

  • Compressor pedal. Sometimes that's all you need.

  • New speakers. Greenbacks are "barky", maybe you'd prefer something "American" voiced, with a hemp cone.

  • Sag Resistor. This is placed in series with your B+ to emulate the resistance of a tube rectifier. As the amp pulls more current (say, during a power chord), proportionally more voltage is dropped across the resistor which feeds your power tubes. It's built-in compression.

  • Higher plate load resistors. This is one of my favorites for increasing the spongy, ragged, in-between-ness of an amp, but it comes at the cost of any crystal cleans. I love a 220k on the preamp triodes.

Without a schematic, it's hard to offer much else.

– Otter

Without ever seeing inside one of Brads amps I would assume he’s integrated those things into his design. Those are old Steve Lucky and Mark Huss mods.

8

You may be right, I don't know anything about 3 Monkey amps. Those are just my go-to first stabs at "browning up" a tube amp. If all that's been done, then my suggestion would be a saggy preamp/od pedal, maybe a Fairfield Barbershop or a Benson Preamp.

An attenuator wouldn't hurt either.

9

Thanks guys... I will pull the chassis out and take some pics.

10

I think the first thing I’ll try is an EQ pedal. Seems everything is just a little too much during rhythm playing. The lead sound is nice. Maybe if I dial back the bass and treble on with an EQ pedal it will smooth out for a nice rhythm tone?

11

Try a 5751 in the V1 position.I use them in all my amps except the ones that originally have a AY7 in V1.I put them in my Boogie MkII C+ drive positions.They make the over drive channel smoother and thicker, less bumblebee like.I use only NOS 5751's, I have found the current production 5751's are like a weak 12AX7.

13

Actually, should you consider it might not be the right amp for you? Will you really be able to change its fundamental response that much?

14

My Vox ac10 is the perfect amp for what I do. I wanted to get the 3 Monkeys amp a little bit closer to the Vox. I enjoy the chase of making things work. I swapped V1 and V2 preamp tubes and it made a pretty significant change in the direction I want to go. Hooked up my Boss EQ and that looks promising.

I will give the power tubes Billy suggested a try. I know different tubes can have a game changing effect on an amp. I have a larger outdoor show coming up on 4/20 that will be the true test. So far I’ve only played the amp indoors and I bought it for larger stages.

15

Also I swapped out the baffle in the cabinet I made from 5/8 ply to 1/2 osb. That made a positive change

16

Post a schematic, & I'll tell you everything thats wrong with it! (kind of a joke, but not really!)

17

Seriously, there's not much we can do without a schematic.

18

I’ll see if I can get a schematic.

19

Gonna take the amp to my local amp tech dude and have him give it a listen.

What I’ve discerned after some time with it is: It’s pretty mid heavy. Using a 7 band EQ to cut the mids is the ticket for a nice rhythm tone. Turn the EQ pedal off and it’s a magical lead tone.

20

Try a 5751 in the V1 position.I use them in all my amps except the ones that originally have a AY7 in V1.I put them in my Boogie MkII C+ drive positions.They make the over drive channel smoother and thicker, less bumblebee like.I use only NOS 5751's, I have found the current production 5751's are like a weak 12AX7.

– stokes

I agree. New 5751s seem to be the 12AX7s that failed the gain test. Lame.

21

Thanks everyone for the input. I’ve tried a few different things and Otter’s suggestion of a compressor was the ticket. It smoothed out the overbearing frequencies. I believe one thing that makes me love my Vox ac10c1 so much is it has a good amount of compression. I ordered a Keely Carvern V2 reverb/delay pedal to add some ambient vibes to my sound.


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