Here are the exact changes I did giving me a much more vintage sound and enabling more play on the clean volume knob at low levels. LEDs GRN LED1 and RED LED2 = 5mm clear (blue when lit up), forward vol. 3,2V High Brightness Diode D2 = BAT42 Schottky (30 V 200 mA) Resistors R1 = 10kΩ -> 23.5kΩ R2 = 1MΩ -> 750kΩ R8 = 560Ω -> 2.2kΩ (vintage/hard rock gain) Capacitor C4 = 220pF These components cost me less than 5€ but turned my Marshall that I never cared for before into a much better amp. Now I use it for practising all the time! Furthermore I removed the original no name 8” speaker and installed a Celestion Ten 30, 10”, 30w speaker in an open back setup. This is not a must but of course it gives a fuller sound. All in all I now prefer my Marshall MG15 over my Spark 40 amp. Unfortunately I haven’t been able to figure out how to change the resistor network for the Overdrive Volume to give it more play at low levels (convenient when practising at home).
Damn that's fucking cool man you took a cheap 100$ practice amp and made it sound way louder and way cooler than how it was originally as a solid state amp props to you.
Hi, I got the same combo 15 gr that hisses too much passing 2 on the clean ch. And the same on the overdrive ch. What could be the guilty? Thanks from Italy.
Wow, I’m amazed this video still gets views… Something you could try to help narrow it down, try plugging into the cd/ line input. Turn the channel controls down, and see if the hiss goes away. Double check your instrument cables. Try plugging the amp into some place different, away from other electronics if possible. If it is still around, then I’d start with the power supply, specifically the filter capacitors. Next suspect would be the amplifier chip itself. If you end up suspecting something in the preamp, I’d do what you can to make it close to how it would have come from the factory. Undo any modifications, replace any capacitors that look suspect to leaking. I don’t have the amp anymore. Check the schematic. Many of these small combos use a TDA2030, which is pretty easy to replace, if you’re handy with an iron! Best of luck!
I modded a Marshall MG10CD to add the external cab jack, with a DPDT switch to change between internal/external speaker, unfortunately although the switch works and it gets the signal out as expected, now the gain potentiometer also increases volume, and the overdrive's volume pot doesn't do much, even at minimum I still get sound
Change it for a Switched Jack, and remember you need to use Speaker Cable NOT a Guitar Cable....Don't need a DPDT to use an external Cab, I do it all the time with cheaper amps as Thrifty says, it's the Driver that is the worse things about these Combos, I've even used a small Epiphone Acoustic Amp with a Peavey 15" Cab and it really does open it up. :)
Cool video, do you know what the forward voltage is on the LEDs you replaced? I found some amber ones that i thought sounded the best. Those little amps are a blast to mod i love it. Just use a standard cliff jack. Most have 4 pins you hook the amp output to the 2 main pins and the speaker to the other. When nothing is plugged in the internal speaker works. When a jack is plugged in the amp then sends the signal out to what ever its plugged into. Its like a little switch built into the cliff jack.
Rondo McBower I'll have to check on the Vf. They are blue LEDs from Mammoth Electronics. I'll have to try the jack like you suggest. That would be much easier than what I'm doing now!
@Crunch Channel, after experimenting with different types and different values I ended up with two identical LEDs. 5mm clear (blue when lit up), forward vol. 3,2V High Brightness. They give a nice vintage Marshall overdrive sound which I like a lot.
Definitely. Whenever I work on amps, I leave them unplugged with the power on, and find something else to do. I found a probe with an LED that I test to see if there is anything left in the power capacitors. If it lights up at all, I walk away again!
@@kkramp1984 I tried that. Didn’t make much of a change. I recommend a Celestion Ten 30 to get a fuller sound. Of course it means you have to cut a larger hole on the front. But it will fit in there. Also I recommend an open back construction.
i want to do this mod, but i'm saving for a 2x12 with 65 watts speakers for a jtm45 head, i don't know if it would work...15 watts with a 65 watts speaker
Si lo haces sube un vídeo, para el amplificador es lo mismo, solo estarías ocupando 15 watts de esos parlantes de 65, lo que no debe ser es que su impedancia sea menor a la de tu amp, si tu amp es de 8 ohm tu gabinete debe ser de 8 ohm si le pones de 4 ohm puedes dañar el amp.
Now make a mod for a dam footswitch. that this 2 channel amp does not support. I got one free with a dean guitar if bought on offerup site. The amp came with the guitar. I put it back on offer up for $45 bucks and no takers after 60 days.
I just did the mod. Way way better. Thank you. I like how the overdrive works now. Much more tones to play.
Wish I had the technical ability to do this to mine. I did the LED mod to a Vox Pathfinder 10 and love the results.
You added a resistor, or you replaced the resistor? And, if you replaced, what is the value of the new resistor?
Great work - any chance you could share the specifics of the resistor change you made?
Here are the exact changes I did giving me a much more vintage sound and enabling more play on the clean volume knob at low levels.
LEDs
GRN LED1 and RED LED2 = 5mm clear (blue when lit up), forward vol. 3,2V High Brightness
Diode
D2 = BAT42 Schottky (30 V 200 mA)
Resistors
R1 = 10kΩ -> 23.5kΩ
R2 = 1MΩ -> 750kΩ
R8 = 560Ω -> 2.2kΩ (vintage/hard rock gain)
Capacitor
C4 = 220pF
These components cost me less than 5€ but turned my Marshall that I never cared for before into a much better amp. Now I use it for practising all the time!
Furthermore I removed the original no name 8” speaker and installed a Celestion Ten 30, 10”, 30w speaker in an open back setup. This is not a must but of course it gives a fuller sound. All in all I now prefer my Marshall MG15 over my Spark 40 amp.
Unfortunately I haven’t been able to figure out how to change the resistor network for the Overdrive Volume to give it more play at low levels (convenient when practising at home).
Damn that's fucking cool man you took a cheap 100$ practice amp and made it sound way louder and way cooler than how it was originally as a solid state amp props to you.
Well done Sir. I like to run mine through Power soak attenuator set to run at 1/2 power (so I can turn it up to 10) through a 2 X 15" bass cabinet .
that's really stupid, it's not a tube amp.
Can I just replace the LEDs without changing the resistor? What kind of effect would that give? Thank you
About g 30 rcd korea is it loud enough for small club?
Play with band
Hi, I got the same combo 15 gr that hisses too much passing 2 on the clean ch. And the same on the overdrive ch. What could be the guilty? Thanks from Italy.
Wow, I’m amazed this video still gets views…
Something you could try to help narrow it down, try plugging into the cd/ line input. Turn the channel controls down, and see if the hiss goes away. Double check your instrument cables. Try plugging the amp into some place different, away from other electronics if possible. If it is still around, then I’d start with the power supply, specifically the filter capacitors. Next suspect would be the amplifier chip itself.
If you end up suspecting something in the preamp, I’d do what you can to make it close to how it would have come from the factory. Undo any modifications, replace any capacitors that look suspect to leaking.
I don’t have the amp anymore. Check the schematic. Many of these small combos use a TDA2030, which is pretty easy to replace, if you’re handy with an iron! Best of luck!
What blue leds & diodes did you use
I modded a Marshall MG10CD to add the external cab jack, with a DPDT switch to change between internal/external speaker, unfortunately although the switch works and it gets the signal out as expected, now the gain potentiometer also increases volume, and the overdrive's volume pot doesn't do much, even at minimum I still get sound
Change it for a Switched Jack, and remember you need to use Speaker Cable NOT a Guitar Cable....Don't need a DPDT to use an external Cab, I do it all the time with cheaper amps as Thrifty says, it's the Driver that is the worse things about these Combos, I've even used a small Epiphone Acoustic Amp with a Peavey 15" Cab and it really does open it up. :)
Cool video, do you know what the forward voltage is on the LEDs you replaced? I found some amber ones that i thought sounded the best. Those little amps are a blast to mod i love it.
Just use a standard cliff jack. Most have 4 pins you hook the amp output to the 2 main pins and the speaker to the other. When nothing is plugged in the internal speaker works. When a jack is plugged in the amp then sends the signal out to what ever its plugged into. Its like a little switch built into the cliff jack.
Rondo McBower I'll have to check on the Vf. They are blue LEDs from Mammoth Electronics.
I'll have to try the jack like you suggest. That would be much easier than what I'm doing now!
@Crunch Channel, after experimenting with different types and different values I ended up with two identical LEDs. 5mm clear (blue when lit up), forward vol. 3,2V High Brightness. They give a nice vintage Marshall overdrive sound which I like a lot.
Cool vid. Do I need to bleed the residue voltage before I start fiddling?
Definitely. Whenever I work on amps, I leave them unplugged with the power on, and find something else to do. I found a probe with an LED that I test to see if there is anything left in the power capacitors. If it lights up at all, I walk away again!
@@kkramp1984 I tried that. Didn’t make much of a change. I recommend a Celestion Ten 30 to get a fuller sound. Of course it means you have to cut a larger hole on the front. But it will fit in there. Also I recommend an open back construction.
please post resistor value
Please see my answer to the comment above
i want to do this mod, but i'm saving for a 2x12 with 65 watts speakers for a jtm45 head, i don't know if it would work...15 watts with a 65 watts speaker
Si lo haces sube un vídeo, para el amplificador es lo mismo, solo estarías ocupando 15 watts de esos parlantes de 65, lo que no debe ser es que su impedancia sea menor a la de tu amp, si tu amp es de 8 ohm tu gabinete debe ser de 8 ohm si le pones de 4 ohm puedes dañar el amp.
nice video, grat job!
Yea I hate that harsh clip I wanna smooth and tighten my 100 head.
Sounds way better. Overdrive sucks stock. I might do the mod.
Now make a mod for a dam footswitch. that this 2 channel amp does not support. I got one free with a dean guitar if bought on offerup site. The amp came with the guitar. I put it back on offer up for $45 bucks and no takers after 60 days.