Layout 5th Generation 183

[talbany]

Max
I don't really think that these MM powered amps were linked to any such preamp specs and IMO could be used and sound good in any of the previous generation amps..So much like an EL-34 Marshall Iron output section or Fender iron 6L6 output section used in the various generations this is a Music man Iron output section..The amp I know of #192 was a 3 piece chassis wooden sides LNFB v1 high plate w Precision PS... The preamp section tone stack was virtually identical to that of 124 after the Skyliner update.. I cannot share any pics as this was a request of the person who gave them to me..This is what I know

Tony

[Max]

Max
I don't really think that these MM powered amps were linked to any such preamp specs and IMO could be used and sound good in any of the previous generation amps..So much like an EL-34 Marshall Iron output section or Fender iron 6L6 output section used in the various generations this is a Music man Iron output section..The amp I know of #192 was a 3 piece chassis wooden sides LNFB v1 high plate w Precision PS... The preamp section tone stack was virtually identical to that of 124 after the Skyliner update.. I cannot share any pics as this was a request of the person who gave them to me..This is what I know

Tony

Hi Tony,

EL 34 or 6L6 in #192? Are you sure #192 has the usual precision PS and not the special "MM power supply", which Chris did find in the ODS with a MM PT he knows?

@chris_sanford:

Thanks for the info.

These skyline circuits in the amps with the MM PTs: Have they been updates or have these MM PT ODS amps been originally built with a skyline circuit? Did these amps with a MM PT that you know all have this kind of front plate layout and script as shown in the attached picture? If not, how did they look then (Here is a thread with pictures of all the ODS generations: https://tubeamparchive.com/viewtopic.ph ... 986#135986 )?

Cheers,

Max

[talbany]

Hey Max
Precision PS and traditional PS.

.The MM amp 192 similar to Precision..
The only real difference would be the B+1 filters since your filtering the higher 700v..and the dropping string.. FWIW.. you can take a Precision PS PCB board from the Bluesmaster layout and with a few minor mods and use it in a MM amp..

MM output Iron is made for EL-34's

[dogears]

I know of several 140s-150s era MM amps. All EL34. All 100 plate loads. All Skyline. All 10uf or 25uf bypass caps on V1! Including the Ultrasound tan Dumble.

192 is a high plate skyline with 6L6 tubes. 4.7 bypass caps on all.... Also has a non standard feedback resistor on the power amp. Less NFB due to the 6L6 tubes. I converted my 192 build to EL34 and preferred the standard 4.7K at that point. Although the 6L6 preferred less NFB.

[chris_sanford]

@chris_sanford:

Thanks for the info.

These skyline circuits in the amps with the MM PTs: Have they been updates or have these MM PT ODS amps been originally built with a skyline circuit? Did these amps with a MM PT that you know all have this kind of front plate layout and script as shown in the attached picture?

Max

Hi Max,

Yes, the amps look like the pic. Three piece chassis with wooden ends, and 'By Howard Dumble' in gold script on the front panel. The skyliner stuff looks to be stock, though it's tough to really say for sure. IIRC, the 'mid' switch was still labeled 'deep' on these amps.

chris

[talbany]

Hi Tony, hi Chris,

And AFAIK at least some of these "goldscript" (classic > skyline transition generation) ODS amps in the 140 - 150 range that Chris knows to have such a MM PT have "classic" circuits, too. But perhaps Chris knows more precisely what preamps and PS circuits have been in these #140 to #150 amps he knows?

Hi Max,

All of the MM amps I know about are Skyliners. The PS is specific to the MM iron, and therefore I do not believe it is correct to call them 'precision power', even though they do have stacked filter caps. IMO, the 'precision' term has more to do with the different dropping string, i.e. the 10k resistor between V2 and V1, along with the lower-than-22k value resistor between the pi and V2 combine to give it 'precision'. The MM amps I'm aware of all have the 22k-2.2k string. Perhaps Tony's example was different though?

Cheers!

chris

Chris.. Just saw your post.. AFAIK The Dropper on 192 was 40k 10 WW to PI 12K to V2 and 2.2k.. Hey if we want to call it MM PS fine by me..

Tony

[Max]

FWIW.. you can take a Precision PS PCB board from the Bluesmaster layout and with a few minor mods and use it in a MM amp.

Hi Tony,

thanks for the info. AFAIR the PS board in the 4th generation "classic" ODS amp with such a MM PT I am familiar with looked like the PS board in your two #124 layouts and not like the PS board in your Bluesmaster layout and have been fitted by Alexander Dumble with 6L6.

MM output Iron is made for EL-34's

AFAIR all of the 4th generation "classic" ODS amps I know and have heard about which have a 4/8 ohm MM OT have been fitted with 6L6 tubes. I have attached a picture of the back of one of these.

@dogears:

Hi Scott,

do the front plates of these amps in the #140 to #150 range with a MM PT that you know look like the one on the picture I attached to my previous post?

All the best,

Max

[Teleguy61]

Thanks for bringing this thread back to business guys.

[Max]

the 'mid' switch was still labeled 'deep' on these amps.

Hi Chris,

that is the reason why I asked if those you know have been updated to skyline specs. These gold script amps are a very small batch of chassis AFAIK (around 10 AFAIK). So IMO it wouldn't have made much sense to label them with a "deep" switch label (and I have never seen or heard of one of these chassis without the "deep" label) if they had been intended to be fitted with skyline circuits from the beginning.

And there is at least one of these goldscripts that I know has been originally built as a "classic" and updated to skyline specs before Joey Brasler of Make'N'Music did lend it to Guitar Player for the big amp shootout in the early nineties (this one btw looks exactly like the Ultrasound EL34 and had EL34 too, so perhaps it is the Ultrasound EL34). This was the one the guitar player testers thought to lack "sweetness" in the OD but is great for "metal tones".

So it would be very interesting to know if those you know have been updated, too, like the one tested in this Guitar Player shootout perhaps being the one today owned by Ultrasound.

Thanks again for the info,

Max

[talbany]

Hi Tony,

thanks for the info. AFAIR the PS board in the 4th generation "classic" ODS amp with such a MM PT I am familiar with looked like the PS board in your two #124 layouts and not like the PS board in your Bluesmaster layout and have been fitted by Alexander Dumble with 6L6.

Max
Have you played any of these amps or by chance have clips of the earlier 140-150..MM.. FWIW..
My MM uses 6L6's and the PS like 124 as well..

Tony

[Max]

Max
Have you played any of these amps or by chance have clips of the earlier 140-150..MM.. FWIW..
My MM uses 6L6's and the PS like 124 as well..

Tony

Tony,

no, I am not familiar in person with a classic > skyline transition generation ODS. That's why I asked Chris and Scott what they know about these amps.

But I know and played two 4th generation "classic" amps with MM iron, AFAIR one with a MM PT and a MM OT and one with a MM OT only.

Cheers,

Max

[chris_sanford]

the 'mid' switch was still labeled 'deep' on these amps.

Hi Chris,

that is the reason why I asked if those you know have been updated to skyline specs. These gold script amps are a very small batch of chassis AFAIK (around 10 AFAIK). So IMO it wouldn't have made much sense to label them with a "deep" switch label (and I have never seen or heard of one of these chassis without the "deep" label) if they had been intended to be fitted with skyline circuits from the beginning.

And there is at least one of these goldscripts that I know has been originally built as a "classic" and updated to skyline specs before Joey Brasler of Make'N'Music did lend it to Guitar Player for the big amp shootout in the early nineties (this one btw looks exactly like the Ultrasound EL34 and had EL34 too, so perhaps it is the Ultrasound EL34). This was the one the guitar player testers thought to lack "sweetness" in the OD but is great for "metal tones".

So it would be very interesting to know if those you know have been updated, too, like the one tested in this Guitar Player shootout, and perhaps the one today owned by Ultrasound.

Thanks again for the info,

Max

Max,

I wouldn't put too much stock in what the panels look like. For instance, this one looks like it should be roughly similar to other black face amps around sn 100, right? However, it's a three-piece chassis w/hrm, Magic Parts iron, 6l6s, and the *real* precision power supply. Oh, and the mid switch is labeled 'deep'.

Question for you, since you mention Joey.. have you ever seen his 'Garage Band Ripper'?

chris

[Mr Dumble]

Thanks for bringing this thread back to business guys.

You are welcome.

[Max]

this one looks like it should be roughly similar to other black face amps around sn 100, right? However, it's a three-piece chassis w/hrm, Magic Parts iron, 6l6s, and the *real* precision power supply. Oh, and the mid switch is labeled 'deep'.

Hi Chris,

Is the amp on this picture you've attached #182? I ask, because AFAIR #182 is the only ODS with this combination of specs and front plate look I have ever heard of. If this is not #182: Around how many amps with exactly this combination of look and specs do you know or have heard of and in what series # range are these?

Question for you, since you mention Joey.. have you ever seen his 'Garage Band Ripper'?

No, I don't know his ripper.

If the classic > skyline transition generation amps you know have been originally built with a skyline or with a classic circuit would perhaps be possible to tell apart by the way the skyline circuit is done in detail, the status quo of the goop in this amp and the code numbers of the pots and the specs of other parts etc.

In all the updated amps I know the update is rather obvious IMO if you take into account all the details in the given amp.

Chris, thanks again for all the info.

Max

@chris_sanford, talbany and dogears:

to avoid misunderstandings and to be able to dig a bit deeper to look if somthing more surfaces by the help of notes or pictures and by doing some calls and sending some mails:

What code numbers (part number, EIA code etc.) precisely did you find on these MM PTs and OTs that you did find in these "MM Dumble amps" you are familiar with?

Cheers,

Max

[erwin_ve]

192 is a high plate skyline with 6L6 tubes. 4.7 bypass caps on all.... Also has a non standard feedback resistor on the power amp. Less NFB due to the 6L6 tubes. I converted my 192 build to EL34 and preferred the standard 4.7K at that point. Although the 6L6 preferred less NFB.

Interesting! What was the value of the GNFB resistor? 10K?