I recently bought this solid state Marshall from late 80’s. Someone had modded it a bit, and it was in worn condition. The switch has been changed, and headphone out was modded to be speaker out. Tolex was ripped from here and there, and the front grill had lost its original colour. Couple of other issues also revealed in closer inspection.
Specifications are as following:
- 50-watt 2-channel solid state
- 12″ Celestion G12M-70 4Ω speaker
- Spring reverb
- Effects loop
Actually 5210 is a solid state version of the 4210 (JCM-800) combo. Although I am a pure tube amp enthusiast, I somehow digged this one. I bought this for 100 euros, and with this money I got quite nice looks, very sturdy cabinet, nice sounding spring reverb and enough but not too much power for home training. Some features still really sucked, so it was time to dissassemble the whole thing into pieces.
The very first thing to do was to change the speaker. The stock Celestion G12M-70 sounded very harsh, so it had to go. As there was a lack of lower end with the stock speaker, I swapped it to Eminence Texas Heat, which is my absolute favourite within all the speakers in the market. Had two Fender Blues Juniors earlier with this speaker, and it always sounded perfect to my ears. Also, it’s known to have warm and fat tone, so it should be a perfect fit with this amp. I also changed the speaker cable to Spectraflex’s cable, and cut it to suitable length:
Next thing to do was to fix the horrible shotgun-like loud pop when shutting off the amp. It’s hardly loud enough to do any harm to speaker, but it can be really annoying to be shot every time after playing. Turning down the volume didn’t help a thing, so something had to be done. In this case, the actual reason for this loud pop seemed to be the DC-power bleeding to the signal path, and due to a sudden voltage change during shutdown the shotgun was fired. In that case it would most probably originate to some power supply’s leaking capacitor. Instead of tracking down the one or changing them all I decided to fix it with the rc snubber, which provides an alternate path for this current to flow during shutdown. Basically, it’s nothing but a 100 ohms resistor and 1uf cap in series between the the two posts in the power switch before the power transformer:
As the cap has to be rated at least 250V or something it’s quite big, but there was well enough space for this assembly. The resistor is hiding below the cap in the picture. As a result the whole explosion is gone. It’s dead quiet during the shutdown now. I also changed the power switch to be more like the original one, because the green rocker switch was ugly to my eyes. I also rerouted some cables under the hood to diminish the disturbances.
The next thing to do was to renovate the front grill. It’s been black earlier, but during the years it had turned to dirty brown. The difference is well visible after removing the Marshall-logo:
Bought some black’n silver grillcloth for 6 euros from the local dealer, and fitted it carefully over the original front panel. After putting the original logo into place it looks very nice to me. After cleaning the tolex with vinyl renovating liquid and glueing all the tears the amp looks like a new. The new switch is also visible in the picture. Too bad my camera somehow warps the pattern in grillcloth.
With some 60 euros I gave this amp a new life. Being a solid state amp it sounds very good after the speaker swap.
Glad I found your post. The amp looks great. I just came across the same amp on Craigslist for $50. Decent condition on the outside but almost all the pots had issues and rendered it unusable. A few hours later it came roaring back to life after I touched up all the solder joints on the pots and output caps (ps caps?) and gave the pots a good cleaning. I used to have the same amp in the tube version and always loved the clean tones but had to give it up after not being able to find anyone who could fix a low power issue it had. So, I’d say the clean tones are comparable on this new amp (punchy, chimey) but the overdrive is useless with the gain set to anything less than 8 1/2, and I’m not really a high-gain player, so…
I’ll probably borrow your idea for the rc snubber. Does the resister need a certain wattage? I like the idea of a speaker jack too. Thanks and good luck.
Hi Moe,
I agree with you. Overdriven sound in this one is quite lame, but I’m used to take it out from my pedals, so this is just OK for me for home use. About the resistor. I used the one rated 4W. It’s surely ”too much”, as 1W Should be well enough.
Attention should be paid also for the capacitor voltage rate. Here in Finland we have the network voltage of 220 volts, so I used the one rated 250 volts.
Cheers,
After hearing a Marshall 5210 on youtube, i was pleased with those sounds, so, i bought one of these, but, the boost channel was total deception as it was so different sounding, sort of fizzy fuzzy distortion, the gain pot is really efficient around 9 -10, has someone experienced this situation before? Thanks.
I have the same amp, and the overdrive control on mine does almost nothing until I get to about 9, then it comes on strong. Kind of a strident, harsh overdrive.
We have this same amp at the house and we changed the noisy pots to new ones, swapped the speaker to the Texas Heat one (found one at a bargain price), and did the snubber mod as well. All good upgrades. Additionally we changed all the 1uF tantalum caps that are in the signal path, to 1uF poly caps (tantalum pots have been reported to give some noise issues). What we find a bit disturbing is that the amp has some idle hum that is independent of the master volume setting i.e. it originates in the PA section. Therefore we swapped the electrolytic filter caps to new ones, hoping that this would kill the hum. No luck. We tried to analyse where the hum is coming from and traced it to the power amp but could not identify any faulty components. While this hum is a minor issue, it would be interesting to know whether it is common to all 5210 amps. Comments anyone? About the boost channel: yes the gain has to be at 9 to give a useful distorted signal, and we are mostly using pedals instead of this channel for good distorted tones.