Germino Update and Question: NOS tubes from Hi Test Guitars

cpa2guitar

Member
Messages
314
Just got off the phone with Greg Germino and then Greg Levy at Hi Test Guitars, as I wanted to buy some NOS tubes for my new Lead 55LV that will arrive later this week. I ended up ordering a matched pair of Mullard EL34’s, XF2, single getter; three Mullard 12AX7s; and one Amperex 12AX7.

Greg G. had told me that, if I ordered NOS tubes for the Lead 55LV, he strongly recommended Mullards; however, when I placed the order, Greg Levy asked me which Mullard EL34s, and I had no clue. So Greg L., who happens to know Greg G., asked me which period of Marshall was the amp that I purchased from Greg G. emulating. When I told him the amp's filtering is period correct for 68/69 JMP-50 specs, he knew which tube to recommend (it's such a pleasure to do business with people who really know their stuff).

Then Greg L. wanted to know whether I wanted the single getter or double getter. At this point, I'm thinking: "geez... I don't know, I just play 'em I don't build 'em... :dunno" So another call back to Greg G, who told me to pick the cheaper of the two, as there is not much difference. The single getter was $25 cheaper and Greg L. had also mentioned the double getter was a bit rolled off in the top end compared with the single getter, so that made it a no-brainer - I went with the single getter.

Greg L. was fine with selling Mullard 12AX7s to me for v2 and v3, but he recommended the Amperex for v1. I went ahead and bought three Mullards, but also bought the Amperex to swap out the Mullard and Amperex in v1 to see which I prefer. Ultimately I'll have one to many 12AX7s, but I figure the one I end up not using in v1 of the Germino can be dropped into one of my amps from 65 Amps.

Greg G. had indicated Greg L. was one of the "good guys" in the NOS tube market, and after talking to Greg L., my instincts tell me Mr. Germino is right. Greg L. was certainly [FONT=&quot]knowledgeable and very helpful.[/FONT] We shall see.

Finally, Greg G. encouraged me to play the Lead 55LV for two or three weeks or even a month before I drop in the NOS tubes. He indicated the Lead 55LV did not need NOS tubes to sound great, but he also indicated the NOS tubes he recommended will make a great amp sound even better. I'll have to post a report on this once I've spent time with the amp with both the stock tubes and the NOS tubes. This should be interesting. If the difference is as great as Greg G. indicated, I'll have to start saving to buy NOS tubes for my 65 Amps models.

Question: I forgot to ask Greg G. about this but I'm confident one of you will know the answer. On the Lead 55LV page of the Germino web site, it states:

"This is the Lead circuit used in original 68-69 JMP-50 1987 models... An incredible sounding amplifier with all the classic late 60's and early 70's sounds. Goes from a slightly crunchy clean to a thick smooth lead tone with just a twist of the guitar's volume control. This is the sound of the famed 1968/69 plexi 1987 model at it's very best." (emphasis added)

I'm a bit confused about what "1987 model" means in this context. Is this amp emulating a 1987 reissue of the 1968/69 plexi, or does it mean something else?

Thanks,

Kirk
 

Third Stone

Member
Messages
948
Both great guys to deal with. To answer your question, what ledzep said above. Number doesn't correspond to the year. There was the model "1959" super lead too, that Marshall came up with in '68, I believe.
 

big mike

Cathode biased
Platinum Supporting Member
Messages
13,418
Both good guys.

Mullards and Amperx in V1-3 is amazing.
You're not messing around going with EL34's too..I usually just concentrate on the preamp tubes.

make sure you rebias/have it rebiased for the new tubes.
 

Phineas Ball

Fuzz
Gold Supporting Member
Messages
2,834
That's going to be quite an amp. I look forward to your tone report. +1 on Greg Germino as quality guy. I bought my Club 40 used and even so G.G. was extremely responsive and just great. I've never worked with Greg L.
 

Dan40

Silver Supporting Member
Messages
1,552
Congratulations on the amp and the fine tubes you purchased. I am running a 70's orange label Amperex in the v1 spot on my 1987 clone and love the tone it gives. I tried a couple of the earlier Bugle Boys but prefer the slightly darker tone this particular orange label produces. RFT's and Tungsram's sound really nice in these amps also!
 

sws1

Member
Messages
11,830
And to your question, it may be that the circuit is the same as a 68/69 plexi, but since you're getting the LV model (low voltage), it can't emulate with 100% accuracy. Pretty darn close though. You'd need to non-LV model to get it 100% right.
 

DICKIE C

Member
Messages
3,982
I think it can and does emulate w/ 100% accuracy. The trannies used in the low-volt are still period correct.

Either way, Greg's amps are plexis, period. They're simply fantastic amps.
 

big mike

Cathode biased
Platinum Supporting Member
Messages
13,418
Voltage Varied quite a bit on originals
The circuit is dead nuts, the voltage allows it to give up the goods a touch earlier.
Not to mention extend tube life
 

Fireball XL5

Silver Supporting Member
Messages
2,984
And to your question, it may be that the circuit is the same as a 68/69 plexi, but since you're getting the LV model (low voltage), it can't emulate with 100% accuracy. Pretty darn close though. You'd need to non-LV model to get it 100% right.
If that's the case I'm confused about this statement from the Germino site?

"The 1202-118 power transformer which is stock for the LV model supplies 425vdc in ss rectifier mode. This model PT was used in the majority of JMP-50 amplifiers from 1967 thru 1969."

Perhaps I'm interpreting the statement incorrectly, but I read this as saying most 50 watt amps from that era ran in that lower 425V range??
 

sws1

Member
Messages
11,830
If that's the case I'm confused about this statement from the Germino site?

"The 1202-118 power transformer which is stock for the LV model supplies 425vdc in ss rectifier mode. This model PT was used in the majority of JMP-50 amplifiers from 1967 thru 1969."

Perhaps I'm interpreting the statement incorrectly, but I read this as saying most 50 watt amps from that era ran in that lower 425V range??
I remember when the LV model came out. I seem to recall Greg built that in response to someone who bought a Lead 55, but wanted lower voltage to soften it up. Maybe they had LV's back in the 60s, but I had interpreted that as it was a mod to lower the output a tad.
 

bandmaster

Member
Messages
819
I bought and buy tubes from Gregg Levy since many years, that guy is a class act. He knows his stuff and always treaded me right. You won't regret it.
 

Fireball XL5

Silver Supporting Member
Messages
2,984
I remember when the LV model came out. I seem to recall Greg built that in response to someone who bought a Lead 55, but wanted lower voltage to soften it up. Maybe they had LV's back in the 60s, but I had interpreted that as it was a mod to lower the output a tad.
Also from the Germino site:

"An optional power transformer 1202-133 is available for those wanting more headroom. Voltage spec increases to 450vdc with ss rectifier."

So if most JMP-50's from that era ran the 1202-118 PT (425V) as opposed to the 1202-133 PT (450V), I assume Greg's Lead 55 LV model to be the more period accurate version??

Obviously my knowledge is limited on this, but curious nonetheless??
 

big mike

Cathode biased
Platinum Supporting Member
Messages
13,418
Splitting hairs really. Most were generally around 450V. Some would be as low as the teens and twenties, and I think I read somewhere that Warren DiMartini's was around 500 V.

Components drift, wall voltages vary, etc etc.

IMO..for a modern amp, 420-440 is fine, and the modern tubes will last using that.
450 DOES sound good, but I doubt most could hear the difference. The headroom will be slightly altered.

Both of mine run 440V FWIW. My favorite of Jim Seavall's 50 watters with the same spec runs 450ish. They're very close in sound. The difference in bright caps makes more difference than the voltage does.

Later on the JMP era, most ran around 390V.
 

big mike

Cathode biased
Platinum Supporting Member
Messages
13,418
I think Greg's also making some allowances with the rectifier tube since some like it tube rectified.
 

cpa2guitar

Member
Messages
314
Both good guys.

Mullards and Amperx in V1-3 is amazing.
You're not messing around going with EL34's too..I usually just concentrate on the preamp tubes.

make sure you rebias/have it rebiased for the new tubes.
Thanks for the reminder big mike. Yes - Greg discussed this with me and encouraged me to purchase the measurement device I will need and rebias the amp myself. I'm not so sure; I am not mechanically inclined and not sure if this would be something I could do effectively or not.

Kirk
 






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