Posts – Sivu 3 – Blackout Electronics

Marshall 5210

Posted on 19.7.2013 by Vesku Posted in Amps .

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.

Blackout Damp Cony

Posted on 17.7.2013 by Vesku Posted in Pedals .

It’s fashionable today to have all the stompboxes true-bypass. But having, let’s say 5 or more true-bypass pedals in the signal path, it _may_ cause problems together with long guitar cables, and you may notice loss of highs. In a nutshell: The longer the signal path, the more resistance there is in it. The more the resistance, the more it affects the high-impedance signal from the guitar.

To fix this you need to put a good-quality buffer in some stage(s) of the line. It’s a good idea to put one in very first in the signal path. Maybe another in very end, but it depends the amount and type of your stompboxes. Note that some germanium-fuzzes don’t want to see a buffer in front of them, so they need to be placed before buffer. Also notice that some pedals already have built-in buffers, even if it’s not stated anywhere. Usually they have a buffered bypass, which means that the buffer is always on, even when the pedal itself is switched off. Due to this, if you are running out of DC-power, the line will be cut because the buffer needs power or it will mute the signal. Pedals known having a built-in buffer:

Most of the Boss pedals
Several Ibanez pedals. I.e all the Tubescreamer TS9/TS-808’s
Most of the Visual Sound pedals. Not sure about he Garage Tone series
Most of the higher end T-Rex pedals. Not sure about the Tonebug series
Mad Professor Ruby Red Booster

I needed a buffer box according to my own special needs. My bass rig has several true-bypass pedals, so I wanted to make sure the signal remains unaffected when running thru the signal path. I also wanted to get the tuner pedal off the line, and furthermore, have a line shutting killswitch in the same box. The buffer itself is like this:

With this beast in your signal path you should be able to use tens of a pedals and miles of a guitar cable without any problem, I’ve been told. The line-out for the tuner pedal needs a signal splitter:

This one divides the input signal for both the always-on tuner out, and for the signal going to the buffer part. At first I builded up the splitter part. I decided to draw the DC-power and grounding wires independently for both boards in case of something goes wrong. It easier to unsolder if the boards are not connected together. This was a wise decision, as the buffer part didn’t work at first try due to one missing link. Let me mention that I didn’t find the reason at 3AM, but I needed to sleep a little first. Got also some bad feedback from my wife about the hullabaloo I caused in the middle of the night.

Splitter part completed:

The killswitch is also connected. It does nothing but mutes the signal. Line out for tuner is still working, as it bypasses the switch. The buffer itself is always on disregarding the switch position. After careful fitting the hole thing fits to 1590B -enclosure:

After attaching some stickers it looks like this:

So what about the name? Recently I ordered some custom stickers for the Dyna Comp clone I bought, and therefore had some spare stickers. I spent some time pondering what could be a suitable anagram using the letters of the word ”Dyna Comp”. So, Blackout Damp Cony it is.

Carlsbro Fuzz from ~70’s

Posted on 13.7.2013 by Vesku Posted in Pedals .

Got this one from my friend, who has got this from someone for free. Pretty interesting case this is. Some features:

Made by Colorsound somewhere in early 70’s
Germanium transistor driven
Wah-sized metal enclosure
Volume-, Fuzz- and Treble-Bass (Tone) -knobs. All are interestingly 100K logarithmic.
Operable only with 9V battery
Is not working

The connection board is made like a cream cake:

Soldering job is remarkably lame, and most of the connections are suprisingly broken. Actually, it seems that someone has messed with this. Maybe tried to fix this. As there is no even indicator light, this looks like totally dead. The very first thing to do is analyze this, and then clone it. After that I need to hunt down some NOS-parts, and try to fix this. To be continued.

Update:

I handed this to Miro, who was ready to buy this disregarding the price. I bartered this with two MXR pedals. Am I totally crazy?

Firstly, this was totally dead, so I wasn’t able to request the eBay price anyhow. Secondly, I owe him some. And thirdly, what’s the price for seeing someone become so overwhelming happy as he did 🙂

After a while he got this working without changing anything but the switch.

Blackout Dalai Llama

Posted on 22.6.2013 by Vesku Posted in Pedals .

So I recently started to build up my own clones out of the commercially produced pedals. I was strongly inspired by Miro from FYA Electronics, who prepared me several custom clones with some modifications (i.e true-bypass Dyna Comp w/ switchable buffer). My intention is not to make any profit with this at this stage, but just produce some pedals for my own use. And have a good time with my new hobby.

As it’s a way more challenging as it seems to be from the first sight, Miro encouraged me to start from some easy layout, and that’s why Red Llama was chosen. Red Llama is somewhat coveted simple overdrive pedal with two knobs. I’ve tried almost every overdrive pedals in this planet so far, so I am always excited to try something new. Overdrive pedals are my weak point, I might say.

The layout is quite simple. Taken from tagboardeffects.blogspot.com, made by IVIark:

After completing the layout, it was time to drill the enclosure. And that’s where the fun starts. The first 10mm holes for 1/4″ jacks were ok. Also the holes for the pots, no problem. As a 12mm hole is needed for the switch and DC-connector, I needed to dig up the good ol’ Perforator from Hell®. That hellish apparatus is capable of penetrating anything from thick steel plate to terrorists’ hideout. Had no bench vice, so I needed to thrust the raw power in my hands. A bad mistake. Perforator (R) divested the enclosure from my hands in no time, and threw it to the moon. This is something to learn. _Always_ mount the enclosure so that you don’t need to stick it with your bare hands. Or. Also, always remember to start with a small hole, and after that drill the final one. After a trip to the moon and back I had some scratches in my nice red enclosure, but nothing serious. After attacking the enclosure again with Perforator® I had all the needed holes. Including a too big hole for the indicator led.

After making all the outboard connections, it was time to put the tagboard into place, and solder the remaining joints:

Nothing beats a total failure after your best shot. Sound is going through when the pedal is switched off, but when switched on the hell gets loose. Nothing but a clean signal spiced with some distant digital buzz. Far away from a good overdriven sound. So what the heck?

Transistor? A short circuit? After checking every connection and component several times I had to admit that the reason for the failure remains secret. So, I created a new one and it worked right away. Later I need to check all the components with multimeter, but now I’ll just complete this job. After adding knobs and some stickers it looks pretty good, and sounds even better.

Let me introduce you: Blackout Dalai Llama:

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