Monoprice 15-Watt, 1x12 Guitar Combo Tube Amplifier with Celestion Speaker & Spring Reverb

[Goldhedge]

15-Watt, 1x12 Guitar Combo Tube Amplifier with Celestion Speaker & Spring Reverb

Ok, it's cheap, but it's a handy little tube amp for $230!

It's not a Fender et al, but it makes noise and it's handy little practice amp with without dragging out the big amp.

What can I do to make it have more tone? Is it possible?

I looked inside and it's circuit board construction. I'd be willing to hard wire it if I could add something to enhance it.
Even use the parts for something better?

3 - 12AX7's pre
2 - EL84's power
Celestion 780 12" speaker


Comments? Suggestions?

Here's a pretty good demo video if interested: https://www.youtube.com/watch?v=RUvsd6-k4xk

[tubeswell]

If you want to convert to a hand-wired amp with those transformers, take a look at any 3 x 12AX7 and 2 x EL84 based amp. For example, you could do a Marshall 18W circuit, or a fender Blues Junior with 1-tube reverb

Or, seeing as how EL84s require 760mA heater juice and 6V6s only require 450mA, convert to octal output tube sockets for a 2 x 6V6 fender based circuit and have enough extra heater juice left over to drive another 2 x 12A_7 tubes, e.g. enough for a Princeton Reverb circuit - or BF Deluxe reverb if you used a MOSFET source follower buffer for the LFO.

[drew]

What can I do to make it have more tone? Is it possible?

That's a bit nebulous . . . Have you tried a different speaker, or a separate speaker cabinet?

Is a schematic available? Couldn't find one in 10 seconds on Google. This amp is probably a re-badged unit from an actual guitar amp company, not some unique -to-Monoprice thing.

[sonicmojo]

Looks like it is Laney based, like a Cub 12R but with different reverb. It's probably not worth messing with that circuit board. Keep as is or gut it and put something completely new in it.

[Stevem]

what is it not providing tone wise now for your needs, I for one have left my Crystal Ball home today if you get my drift?

[JazzGuitarGimp]

what is it not providing tone wise now for your needs, I for one have left my Crystal Ball home today if you get my drift?

C'mon stevem, get with the times, man! There is now a "Crystal Ball" app for most mobile devices....

[Goldhedge]

If you want to convert to a hand-wired amp with those transformers, take a look at any 3 x 12AX7 and 2 x EL84 based amp. For example, you could do a Marshall 18W circuit, or a fender Blues Junior with 1-tube reverb

Or, seeing as how EL84s require 760mA heater juice and 6V6s only require 450mA, convert to octal output tube sockets for a 2 x 6V6 fender based circuit and have enough extra heater juice left over to drive another 2 x 12A_7 tubes, e.g. enough for a Princeton Reverb circuit - or BF Deluxe reverb if you used a MOSFET source follower buffer for the LFO.

Thanks for the best answer tubeswell. Gutting it is not out of the realm of possibilities! Is there a schematic for the Princeton Reverb you're talking about?

I think it's a Laney knockoff?

I was hoping to make it sound like a Dumble for those who don't have a crystal ball...

[tubeswell]

Is there a schematic for the Princeton Reverb you're talking about? ...

http://el34world.com/charts/Schematics/ ... AA1164.pdf

I was hoping to make it sound like a Dumble ...

http://ampgarage.com/forum/viewforum.php?f=5

http://el34world.com/charts/Schematics/ ... matics.htm

[drew]

It's apparently a Laney Cub 12R:

http://www.electricalaudio.com/phpBB3/v ... &p=1972661

https://ampstack.wordpress.com/2013/05/ ... ombo-guts/

http://www.laney.co.uk/products/cub12r/

It's a PCB amp with board-mounted sockets and a very small chassis. To me, it would be a lousy candidate to try to make into something else. If you can't get the sound you want from some combination of tube- and speaker-rolling and pedals, I would move on from it.

[tubeswell]

Interesting - Looks like there's enough room in that Laney Cub chassis for hand-wiring a new circuit (including mounting fresh sockets etc). Another option could be to obtain a compatible fender tweed type chassis that would fit into the gap (or fabricate your own tweed style chassis from 2mm aluminium).

But as drew implies, the pennies start to add up. If you really want to get into exploring your inner craving to make and mod tube amps, be aware that there is a price to pay.