71 specs 50 watt clip on youtube

[Geetarpicker]

Here are videos of my original '70 lead spec Marshall 50 full stack w/'59 burst. Scroll down to the ones from "1981", yep these were filmed "back in the day"...

http://www.youtube.com/user/GlenKuykendall" onclick="window.open(this.href);return false;

I'm actually looking for this exact amp that I sold back in '83. IT actually came up on ebay much more recently but I sadly missed it!!! It's out there, maybe not to far away... Serial # 5297A

That said if I can't find my original, I'm probably going to buy a Metro '68 50 kit and mod it to the later specs. Time to buy I guess before the sale runs out! I'm pretty sure mine circuit wise was setup just like the one in those "71 spec" Youtube clips, though mine was dated 10-3-70. Would that actually be March 10, 1970 the way the Brits read it?

In some ways I think my '70 might have been a tad gainer than the new clone in Metros clips. Might have just been the guitar though.

[yngwie308]

Glen, I posted these in the Artists section, under your name
yngwie308

[budubum]

Here are videos of my original '70 lead spec Marshall 50 full stack w/'59 burst. Scroll down to the ones from "1981", yep these were filmed "back in the day"...

http://www.youtube.com/user/GlenKuykendall" onclick="window.open(this.href);return false;

I'm actually looking for this exact amp that I sold back in '83. IT actually came up on ebay much more recently but I sadly missed it!!! It's out there, maybe not to far away... Serial # 5297A

That said if I can't find my original, I'm probably going to buy a Metro '68 50 kit and mod it to the later specs. Time to buy I guess before the sale runs out! I'm pretty sure mine circuit wise was setup just like the one in those "71 spec" Youtube clips, though mine was dated 10-3-70. Would that actually be March 10, 1970 the way the Brits read it?

In some ways I think my '70 might have been a tad gainer than the new clone in Metros clips. Might have just been the guitar though.

hi glen.

on your video said: Glen Kuykendall circa 1981 live with "RAVEN" Pt.1

did you ever used a stompbox to boost the signal or a disto/OD pedal?
what speakers were in those 2x 4x12 cabs?

[yngwie308]

If I may speak for what I read of what Glen said, he says he may have had an Altair or Scholtz attenuator or maybe just a cranked wide open amp. No pedals for distortion or boost were used...
yngwie308

[budubum]

If I may speak for what I read of what Glen said, he says he may have had an Altair or Scholtz attenuator or maybe just a cranked wide open amp. No pedals for distortion or boost were used...
yngwie308

thanks for your input yngwie. i want to be sure if he did or not did.

could you verify what yngwie just told me?

thanks

[Geetarpicker]

Yep, a flange, chorus, wah, on/off, but no boosts or overdrives. The two 4x12 cabs I bought new in 76-77 and had blackback 75hz G12H 30s.

[budubum]

Yep, a flange, chorus, wah, on/off, but no boosts or overdrives. The two 4x12 cabs I bought new in 76-77 and had blackback 75hz G12H 30s.

thanks man i appreciate these.

i must say thats one a heck of a gainy plexi. whats even more lucky is in those days, you could still crank an amp without getting cops on your tail, right?

so this means that you also used an attenuator`like yngwie said? and whats an altair?

thanks

[Geetarpicker]

I had two attenuators back then, an Altair circa '78 or so and a Scholz power soak and those came out around '81. I'm pretty sure I was using the Scholz attenuator in these videos as I think I can see it's blue faceplate on the ground off to the left of the stack. I was however probably playing fairly loud as it was outside, maybe just a click or two down on the attenuator plus running two cabs full of G12Hs is loud too. That '70 Marshall 50 amp had a split cathode setup, with the .68 cap on the 1st and 2nd stage. I'm not sure which feedback resistor it had or where it was tapped off the output. I do remember it was a particularly hot running 50 with a pretty strong B+.

If anyone see this '70 small box 50 SN# 5297A I'd love to buy it back. Oddly it has a factory rotary ohms selector typical for a short period in '70.

http://www.youtube.com/user/GlenKuykendall" onclick="window.open(this.href);return false;

[eddie25]

So is that a F&T 50uf/50uf dual axial on the board?

If so, where can I get one?

[Kitarist]

is there a layout available for the 71 specs ? someone can show it ?

It is with just a few exceptions, but the "71" metal panel 50 watt is almost identical to the "68" plexi 50 watt.

Screenshots from MetroAmp 50w Instruction Manual -- "Thanks, MetroAmp!"

"Plexi" Era


"Metal Panel" Era


Notes:

1.) The V1B plate bypass cap is changed from the Plexi (0.022uf) to the Metal Panel (0.0022uf).

2.) The 33+33uf filter that found in the middle of the preamp boards on the 1968 era 50w, it is raised by 1971 to 50+50u. Also the 50+50u is now in many cases no longer on the board, but instead, on the chassis surface.

3.) The NFB resistor is changed from the Plexi (47k) to the Metal Panel (100k). The NFB resistor on some later Metal Panel (100k) is hard wired to the 4 ohm tap. These later Metal Panels with this setup generally had no 0.68uf cap on V2.

4.) With the extra 0.68uf on V2, having the 100k on the 4 ohm tap can get a bit mushy. So 47k on to the 8 ohm tap (if using a 8 ohm cab) seems to be the popular preference for these.

5.) Some later Metal Panel amps use 25k pot for the presence control, instead of the 5k pot, and instead of the 0.1uf cap on the presence, they use instead a 0.68uf cap, along with a 4.7k resistor.

6.) A 5000pf bright cap was used on later Metal Panels.

EDIT: Photos updated

Can someone please repost the layouts?

Thanks!!!

[Roe]

is there a layout available for the 71 specs ? someone can show it ?

It is with just a few exceptions, but the "71" metal panel 50 watt is almost identical to the "68" plexi 50 watt.

Screenshots from MetroAmp 50w Instruction Manual -- "Thanks, MetroAmp!"

"Plexi" Era


"Metal Panel" Era


Notes:

1.) The V1B plate bypass cap is changed from the Plexi (0.022uf) to the Metal Panel (0.0022uf).

2.) The 33+33uf filter that found in the middle of the preamp boards on the 1968 era 50w, it is raised by 1971 to 50+50u. Also the 50+50u is now in many cases no longer on the board, but instead, on the chassis surface.

3.) The NFB resistor is changed from the Plexi (47k) to the Metal Panel (100k). The NFB resistor on some later Metal Panel (100k) is hard wired to the 4 ohm tap. These later Metal Panels with this setup generally had no 0.68uf cap on V2.

4.) With the extra 0.68uf on V2, having the 100k on the 4 ohm tap can get a bit mushy. So 47k on to the 8 ohm tap (if using a 8 ohm cab) seems to be the popular preference for these.

5.) Some later Metal Panel amps use 25k pot for the presence control, instead of the 5k pot, and instead of the 0.1uf cap on the presence, they use instead a 0.68uf cap, along with a 4.7k resistor.

6.) A 5000pf bright cap was used on later Metal Panels.

EDIT: Photos updated

Can someone please repost the layouts?

Thanks!!!

everything but 5 is found in the 50w instructions

[fhn_lopes]

I have a 1976 JMP50 with a metro board 71' specs, and it's not sounding full and gainy as this clips.. I use a Fender HSS with Bare Knuckles VHII on the bridge, and the sound is too thin from what I thought it would be, and less gainy too.

I compared it with an 1980 bassman70 and the BM kicked ass, a real bit more gain and more punch as well. Of course it's a 70w with 6L6 but the marshall is too thin and probably should be more gainy than the bassman70. Both amps were volume on 10, and the JMP was DIMED all pots except the presence arround 4. The bassman was bass 3 and treble 6, normal channel.

Is there anythinh wrong with my JMP or sometimes it just happends ?? s there any easy tricks to fix this? The low end of the JMP is really week, not punchy, les punchy than a 50w JCM800...

[PCollen]

Just perusing through the forum, and reading this thread. Great tone on that '71 spec 50W'er video, G. But it begs the question: just exactly what are the " '71 specs " for the 50 W'er. I assume it's a Model 1987, but were the specs different for '71 vs. '70 or '72 ?

[tfrost33]

Any Chance for a more hi Def pic of this amp/circuit. I am replicating this build somewhat. I had Brian H make me a perf board for my amp and I am stuck on a particular area concerning the bias pot and rectifier diodes, and the buss wire. In particular the bare buss wire on the lower right corner of the board per the metro 50 watt kit instructions.

thank you

Tony

[toolowd]

That's my amp!

Original 71 smally and 4x1 w black backs!

Love it!