Germino Lead 55 Trouble - We Summon The Amp Gods:

Now here's something else to think about. The last time I tried to use Tung-Sol EL34B power tubes in an older style Marshall I had to max out the bias pot to even get close to a reasonable level. If that amp was biased to the EL34B's I would venture to guess that you will be way to hot with the Svetlanas in there. Of course if nobody biased the amp when the Tung-Sols were installed the point is moot.
 
Thanks for the links. I was in a rush to get this delivered, but i ended up seeing around 34-35Ma with 464VDC plate voltages...on the cool side, where i would rather be.

We spent a few hours jammin together last night. He is hitting this amp with a Pro-Co Rat. Previously, it sounded like it was frying eggs at idle. Now, it's dead quiet...I'm not kidding. He thought it didnt power up at first.

The 83S/83S/82 tube rollout totally transformed the amplifier. It was decent when i started on it, but it was really satisfying to see his jaw go slack as he started playing it.

It's BIGGER sounding at all volume levels. The gain is much more refined and the amp responds to pick attack more evenly and cleanly, but the BEST and nost noticeable change is how much more responsive the tone controls are.

Each setting was lowered while giving him the tone he wanted. Treble was maxxed out as i received the amp and now, the treble had to be backed off roughly two dial positions to get the same tone. This is with every knob position on his rig either paint marked or written down, so we know exactly where it was before.

My observations:

This early Marshall design is revered and I've considered building one for myself. Here are my take-aways...

Ok. I tried every tube combo i had on hand in this amp to arrive where i am now. I also tried the jumper between the 1 & 2 inputs and, not only did i not like the tone, my daughter complained of a high pitched noise coming from the amp with the jumper in place that i couldn't hear.

83S/83S/82 beat everything, even vintage Jan Phillips and GE. No contest.

This amp sounds great, but it really does take the ProCo Rat to get it to sound good. Without that pedal, i wouldn't give this amp the time of day. That pedal MAKES this amp. Period...

But, compared to my DSL40C (he's had one of mine on loan for a week) and my full pedalboard, its hard to pick a winner between the two of them.

Now, keep in mind that all my DSL40C'S run the Electro-Harmonix 12VR75 speaker and ECC823/5751/ECC83MG/5751 pre-amp tube rollout, with Electro-harmonix EL-34's and biased around 28-32Ma, so while they di not have any permanent mods like 'C19' etc., they are also not stock.

Running my DSL40C, through his twin 4x12 Germino cabinets, i couldn't tell a huge difference between the two amps and even the owner commented on how he was expecting the PTP Germino to just blow the DSL40C away and it didn't.

I have to give the PTP the nod over PCB. Much more reliable and easier to fix too.

I don't like not having reverb (personally) but that's just a personal thing. I also don't dig the two volumes and no dedicated gain knob, but again, this is where the ProCo Rat comes into play. Even with three Genelex B759 Gold Lion's it won't produce any real gain on it's own...at least not enough to catch my ear so to speak.

It will nail Angus & Malcolm all day long, but that's all you are gonna get without an overdrive - and that's ok.

If i was building one for myself, I would install a cooling fan in the single, square opening in the back cover. I would also machine a 3/4" hole on each side of the chassis (above the mounting flanges) and open twin 2" holes in the floor of the cabinet and screen them, to bring airflow up and onto resistors, out the holes in the chassis and out through the screen in the rear of the box.

I think the aluminum sheet in the floor of the box and no cooling is a mistake.

But, after playing all these Holt Grail amps again, i am just not blown away by them like i was hoping to be.

Thinking i might just convert one of my DSL40C'S to a head for now and take a rain check on building my own PTP 45 watt for now...

20200301_144215.jpg
 
Robert Herndon said:
Thanks for the links. I was in a rush to get this delivered, but i ended up seeing around 34-35Ma with 464VDC plate voltages...on the cool side, where i would rather be.

We spent a few hours jammin together last night. He is hitting this amp with a Pro-Co Rat. Previously, it sounded like it was frying eggs at idle. Now, it's dead quiet...I'm not kidding. He thought it didnt power up at first.

The 83S/83S/82 tube rollout totally transformed the amplifier. It was decent when i started on it, but it was really satisfying to see his jaw go slack as he started playing it.

It's BIGGER sounding at all volume levels. The gain is much more refined and the amp responds to pick attack more evenly and cleanly, but the BEST and nost noticeable change is how much more responsive the tone controls are.

Each setting was lowered while giving him the tone he wanted. Treble was maxxed out as i received the amp and now, the treble had to be backed off roughly two dial positions to get the same tone. This is with every knob position on his rig either paint marked or written down, so we know exactly where it was before.

My observations:

This early Marshall design is revered and I've considered building one for myself. Here are my take-aways...

Ok. I tried every tube combo i had on hand in this amp to arrive where i am now. I also tried the jumper between the 1 & 2 inputs and, not only did i not like the tone, my daughter complained of a high pitched noise coming from the amp with the jumper in place that i couldn't hear.

83S/83S/82 beat everything, even vintage Jan Phillips and GE. No contest.

This amp sounds great, but it really does take the ProCo Rat to get it to sound good. Without that pedal, i wouldn't give this amp the time of day. That pedal MAKES this amp. Period...

But, compared to my DSL40C (he's had one of mine on loan for a week) and my full pedalboard, its hard to pick a winner between the two of them.

Now, keep in mind that all my DSL40C'S run the Electro-Harmonix 12VR75 speaker and ECC823/5751/ECC83MG/5751 pre-amp tube rollout, with Electro-harmonix EL-34's and biased around 28-32Ma, so while they di not have any permanent mods like 'C19' etc., they are also not stock.

Running my DSL40C, through his twin 4x12 Germino cabinets, i couldn't tell a huge difference between the two amps and even the owner commented on how he was expecting the PTP Germino to just blow the DSL40C away and it didn't.

I have to give the PTP the nod over PCB. Much more reliable and easier to fix too.

I don't like not having reverb (personally) but that's just a personal thing. I also don't dig the two volumes and no dedicated gain knob, but again, this is where the ProCo Rat comes into play. Even with three Genelex B759 Gold Lion's it won't produce any real gain on it's own...at least not enough to catch my ear so to speak.

It will nail Angus & Malcolm all day long, but that's all you are gonna get without an overdrive - and that's ok.

If i was building one for myself, I would install a cooling fan in the single, square opening in the back cover. I would also machine a 3/4" hole on each side of the chassis (above the mounting flanges) and open twin 2" holes in the floor of the cabinet and screen them, to bring airflow up and onto resistors, out the holes in the chassis and out through the screen in the rear of the box.

I think the aluminum sheet in the floor of the box and no cooling is a mistake.

But, after playing all these Holt Grail amps again, i am just not blown away by them like i was hoping to be.

Thinking i might just convert one of my DSL40C'S to a head for now and take a rain check on building my own PTP 45 watt for now...

View attachment 39387
Click to expand...

If the bias is set cold the output tubes shut off at idle, which is why you hear no noise. The output tubes act like a noise gate when biased cold.
No wonder it's dead quiet.
If the amp is biased correctly, usually you will hear hiss noise because the output is not shut off at idle. Noise is normal.
Cold bias causes crossover distortion which is what most people are trying to get rid of, that's why Marshall amps are biased hot a lot of the time.
 
Amp Mad Scientist said:
If the bias is set cold the output tubes shut off at idle, which is why you hear no noise. The output tubes act like a noise gate when biased cold.
No wonder it's dead quiet.
If the amp is biased correctly, usually you will hear hiss noise because the output is not shut off at idle. Noise is normal.
Cold bias causes crossover distortion which is what most people are trying to get rid of, that's why Marshall amps are biased hot a lot of the time.
Click to expand...

I must admit that i have arrived at the point where i am putting less and less thought into equipment and more into just playing and making a living doing so. My main concern was that the bias wasn't excessively "off the mark" either one way or the other. I didn't give it much more thought than that.

I was actually a little intimidated by this amp at first, but i got past that.

The owner just loves the amp now and it works for him on a daily basis, so i think we got him to a good place.

The ECC82 really gave the amp a very natural, smooth and full overdrive...
 
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