Park 75

[cpollack]

So here's something that's been nagging at me for a while:

What circuit, iron, and voltages are used in the mythical Park 75 like the red one in the Pitman book? I haven't been able to locate a schematic and have heard all sorts of vague non-verifiable bits like "It has KT-88s and a hotter preamp" (how is it 'hotter'?) to "It's just a 50-watt Marshall with KT-88s" (which 50-watt Marshall?). About the only agreement I've seen is that it has a pair of KT-88s. The photos also tell us it has a different input jack arrangement from Marshalls of the same era.

Thanks in advance.

[Reeltarded]

Mine have had EL34s or late one 6550s.

I never thought they actually meant 75 watts, I always considered it was a marketing scheme and some proof that they were actually different without actual differences. I have had 2 earlyish ones and a single later one like 73-4 (?) with the alien tech control markings.

Different insides? Early ones I doubt much different, later one had to. It was terrible. They all 3 leaned a little to the bright side but decidedly Marshall.

[Roe]

just a 50w w/kt88s. there's some on the marstran pagehttp://marstran.com/69%20362.htmhttp://marstran.com/Historic%20Data%20Base.htm

[Reeltarded]

And there is the beans!

How's Lars and his project coming along, Roe?

[Roe]

And there is the beans!

How's Lars and his project coming along, Roe?

He's restporing two majors now. He has collected most of the parts but are still looking for a few things. I guess he'll try to start them up soon D:

[cpollack]

Perfect, thanks for the replies.

[LeftyStrat]

On a related note, wasn't there a Park 100w that had a 2.5k primary? Can't find the reference now, but I believe it was Ken Fischer saying something about this model sounding really good.

P.S. First post in the Marshall TAG forum! Woot! Thanks Allyn and HeeBGB!

[Roe]

[quote="LeftyStrat"]On a related note, wasn't there a Park 100w that had a 2.5k primary? Can't find the reference now, but I believe it was Ken Fischer saying something about this model sounding really good.

P.S. First post in the Marshall TAG forum! Woot! Thanks Allyn and HeeBGB![/quoute]

the 2k5 appears to have been an anomaly. these were typically 4k at first and 1k75 later

[Dingleberry]

Quote from article: "Ken Fischer's ideas of plexi'ying metalface Marshals"

*primary output impedance levels: -very early Marshall Plexis with Geneflex KT66's had very high plate voltage and 3200 Ohm plate load through two 50watt Partridge trannys, chassis were made of aluminum which affects fields of trannys and therefore tone ... forget about reproducing the sound of those plexis.

-primary impedance on the output tranny was around 2500 up to 1965 on main versions,

-following 1967 it went down to around 1750 Ohms with smaller output tranny and EL-34's, this gave the response a more raw and bitting quality. Best sounding are Parks at 2500 Ohms.

But now it gets interesting. I'm fine tuning my "ultimate Marshall" scratch build at the moment and I have a Drake 783-257 OT in it. It is from a canadian market early eighties 50W JMP. It has 2k5 primary Z and it sounds really great. So either 2 or 4 x EL34 the 2k5 will work and can sound great.
-T

[Reeltarded]

There are a few 100s with a 2k2 as well. That 2k2-2k5 range ssems to be menacing and awesome. Lovely even.

[groovtubin]

And there is the beans!

How's Lars and his project coming along, Roe?

He's restporing two majors now. He has collected most of the parts but are still looking for a few things. I guess he'll try to start them up soon D:

I have a few of the ceramic round resistors!

jim

[Reeltarded]

Jim, you have a PM. I need a close quad.

[67plexi]

My Park 75 has a JTM 45 pre amp of sorts GEC KT88 680 volts B+ . 550 volts under load.
Early 1969 serial number A-1048 Marshall put the 1 on the serial number like they made more
amps so this one would be #48 Park in 1969 I don't think Park/Marshall made to many amps.
OPT 784-138 not 784-139 like most 50 watt plexi Marshalls. The PT and choke are not readable.

Steve.

[groovtubin]

Jim, you have a PM. I need a close quad.

three on the way Miles! SO sorry i didn`t havem all!



jim

[Reeltarded]

Yay! Last inop of the Majors for a while. Now I just need a set of tubes that won't melt like glass candles. Billy's neighbors are going to hate him!

hehe!