I expected this amp to be built like junk, it is not rather it is quite nice and the YouTube reviews are excellent:
Complain about a power cord, come on guys, really?
$238 on Monoprice now, free shipping, some have found coupons for about $200! $279 normally.
https://www.monoprice.com/Product?p_id=611815
$249 on Amazon.
This amp looks very much like the Fender Blues Junior (FBJ) but with some interesting advantages:
EL84 s like the FBJ
Effects loop, none on the FBJ
Switch for 1W practice mode
Adjustable fixed bias design, the Blues Junior has no adjustment and comes with the tubes biased above the max rating
Celestion speaker, cheap one of course
Disadvantages:
Hum, passable but should be better. Edit: Hum is not bad at normal volume settings.
Reverb and effects loop are buffered with TLO72 op amps as is done with most "modern" Fenders
Fuse is internal
No screen grid stoppers resistors on the output tubes
Cheap caps
I bought a very early one used for $125 thinking that it was worth it for the box, chassis reverb tank and speaker.
It is Tweed like in that the controls point up, rather than forward as on the latest production - I believe that the
design is the same.
I'd rebuild it and use it for parts if we don't like it.
This was claimed to have new tubes, a MOD reverb tank and it has an Eminence Legend 12" speaker.
Opened it up and the layout is completely different from the FBJ and not good IMO but should not
be too hard to work on for basics but if any of the surface mount components has to be changed then
it is probably not worth having a shop fix it, and a DIYer will need surface mount skills to do it.
Tubes are JJ s with V1 being a Tung Sol Russian reissue
It has some mods one being a "Neg Feedback" control
Found a schematic not sure if it is early or late, tempted to remove the mods.
Edit: I've decided that it will not be easy to work on so I'll leave the mod in place and let my son try it.
The price was certainly worth it for the case, chassis, speaker, tubes and reverb tank so no loss.
Previous owner told me that the work was done by an amp tech in MA who sold it to him.
If anyone knows of documented mods I'd like to see if those are the ones in this unit, please post a link.
Complain about a power cord, come on guys, really?
$238 on Monoprice now, free shipping, some have found coupons for about $200! $279 normally.
https://www.monoprice.com/Product?p_id=611815
$249 on Amazon.
This amp looks very much like the Fender Blues Junior (FBJ) but with some interesting advantages:
EL84 s like the FBJ
Effects loop, none on the FBJ
Switch for 1W practice mode
Adjustable fixed bias design, the Blues Junior has no adjustment and comes with the tubes biased above the max rating
Celestion speaker, cheap one of course
Disadvantages:
Hum, passable but should be better. Edit: Hum is not bad at normal volume settings.
Reverb and effects loop are buffered with TLO72 op amps as is done with most "modern" Fenders
Fuse is internal
No screen grid stoppers resistors on the output tubes
Cheap caps
I bought a very early one used for $125 thinking that it was worth it for the box, chassis reverb tank and speaker.
It is Tweed like in that the controls point up, rather than forward as on the latest production - I believe that the
design is the same.
I'd rebuild it and use it for parts if we don't like it.
This was claimed to have new tubes, a MOD reverb tank and it has an Eminence Legend 12" speaker.
Opened it up and the layout is completely different from the FBJ and not good IMO but should not
be too hard to work on for basics but if any of the surface mount components has to be changed then
it is probably not worth having a shop fix it, and a DIYer will need surface mount skills to do it.
Tubes are JJ s with V1 being a Tung Sol Russian reissue
It has some mods one being a "Neg Feedback" control
Found a schematic not sure if it is early or late, tempted to remove the mods.
Edit: I've decided that it will not be easy to work on so I'll leave the mod in place and let my son try it.
The price was certainly worth it for the case, chassis, speaker, tubes and reverb tank so no loss.
Previous owner told me that the work was done by an amp tech in MA who sold it to him.
If anyone knows of documented mods I'd like to see if those are the ones in this unit, please post a link.
Last edited:
This is a discussion about the early model (roughly 2016) like ours with the controls pointing up rather
than forward as they are on the latest version:
http://markweinguitarlessons.com/forums/threads/monoprice-15w-tube-amp-laney-12r-review.73085/
than forward as they are on the latest version:
http://markweinguitarlessons.com/forums/threads/monoprice-15w-tube-amp-laney-12r-review.73085/
My son finally came to get this amp and tried it out. It works great as a clean amp, but as he turns the gain,
up past 5 and plays it hard it sounds great for about 10 seconds and then the volume drops to almost
nothing and it crackles when he plays loudly. The very weird thing is that it seems to latch into this mode
and cycling power for say 20 seconds doesn't clear it. I don't know if leaving it off for say 5 minutes would
clear it, that's an experiment that we have to do. He seemed to think that playing it softly for a minute or
two also clears it. But who knows perhaps silence for a few minutes would also clear it, another experiment to do.
He liked the clean sound so much that he decided to take it, he mainly plans to use it for clean.
Also, it did it with his very nice PRS guitar with hum buckers,
but it didn't seem to do it with my very cheap Peavy guitar with single coils.
I'll need to test it out on the bench and see if I can get it to latch up, then probe voltages etc.
I had a passing thought that it might be an oscillation but you'd think that turning it off would clear that.
Any tips and suggestions would be appreciated.
The plan from the start was to use the box, chassis, tubes transformers, etc. and toss the circuit board if it was
no good, this was further reinforced when I saw that the circuit board had a good amount of surface mount
parts. I'll fix it if I trace it down to a cold solder joint, dirty relay contacts or just a bad through hole part but
if it becomes a time sink to fix I'll just build a hard wired Vox, Tiny Terror, or Blues Jr design in it. Since he likes
it so much he'll probably buy a new one if we decide to gut this one.
up past 5 and plays it hard it sounds great for about 10 seconds and then the volume drops to almost
nothing and it crackles when he plays loudly. The very weird thing is that it seems to latch into this mode
and cycling power for say 20 seconds doesn't clear it. I don't know if leaving it off for say 5 minutes would
clear it, that's an experiment that we have to do. He seemed to think that playing it softly for a minute or
two also clears it. But who knows perhaps silence for a few minutes would also clear it, another experiment to do.
He liked the clean sound so much that he decided to take it, he mainly plans to use it for clean.
Also, it did it with his very nice PRS guitar with hum buckers,
but it didn't seem to do it with my very cheap Peavy guitar with single coils.
I'll need to test it out on the bench and see if I can get it to latch up, then probe voltages etc.
I had a passing thought that it might be an oscillation but you'd think that turning it off would clear that.
Any tips and suggestions would be appreciated.
The plan from the start was to use the box, chassis, tubes transformers, etc. and toss the circuit board if it was
no good, this was further reinforced when I saw that the circuit board had a good amount of surface mount
parts. I'll fix it if I trace it down to a cold solder joint, dirty relay contacts or just a bad through hole part but
if it becomes a time sink to fix I'll just build a hard wired Vox, Tiny Terror, or Blues Jr design in it. Since he likes
it so much he'll probably buy a new one if we decide to gut this one.
Last edited:
Video showing some mods:
Forum discussion about the mod:
https://www.tdpri.com/threads/monoprice-15-watt-tube-amp.609524/page-35#post-8522889
Forum discussion about the mod:
https://www.tdpri.com/threads/monoprice-15-watt-tube-amp.609524/page-35#post-8522889
I just bought one of those amps. The Monoprice 15-watt with front-facing knobs. I bought it brand new from Monoprice. It snapped, crackled and popped like crazy. I was able to dial in some good tones. It's plenty loud. But, I couldn't get past all the noise, I talked to Monoprice and they told me to send it back. I brought it to FedEx today. I hope the replacement is better. I've read a lot of good things about this amp.