Am servicing a Dean Markley T60. The HV secondary went shorted and there's a considerable amount of rust on the transformers.
Does anyone know where I can find a replacement for this transformer?
Also, does anyone have schematics with the transformer ratings? The links I've found in past forum discussions are all dead now.
Does anyone know where I can find a replacement for this transformer?
Also, does anyone have schematics with the transformer ratings? The links I've found in past forum discussions are all dead now.
I notice this fault seems to be a common one as a guy called Monodogenerator who inhabits a few websites is asking the same question as he has got one that somebody has changed because of that fault ---only its the wrong voltages.
Nobody replied.
Another of the same on a musicians website in this case DCM80 amps --
answer -- "schematic doesn't list any specs but using the main filter caps rated at 35V DC works out at a 42-48V AC ct transformer".
Schematic for preamp/power supply can be downloaded here-
dean markley t120r
No power output voltages provided.
Nobody replied.
Another of the same on a musicians website in this case DCM80 amps --
answer -- "schematic doesn't list any specs but using the main filter caps rated at 35V DC works out at a 42-48V AC ct transformer".
Schematic for preamp/power supply can be downloaded here-
dean markley t120r
No power output voltages provided.
The transformer in question has high voltage secondary for tube power. Probably on the order of 750V on that winding normally. It has another winding which I suspect is low voltage and then a 6.3V winding.
Having a schematic of the original power supply would be helpful in determining what it is that the supply provides in terms of voltage and current to various parts of the amplifier.
Having a schematic of the original power supply would be helpful in determining what it is that the supply provides in terms of voltage and current to various parts of the amplifier.
Their website seems to be poorly designed. Can't find any contact info for them, just a Facebook and Instagram link. Anyone have a phone number?
17505 N.79th Ave,
suite 307,
Glendale,
Arizona 85308
or through - John Weaver,
Blackhawk Management Group,Inc.
I get the impression he is either retired or doesn't want direct public involvement.
The USA --National Association of Music has a webpage where they cant get info on him ---a Dan Del Fiorentino of the above also has a webpage which if you fill in you can message him asking if he has found him.
Contact Dand | NAMM.org
suite 307,
Glendale,
Arizona 85308
or through - John Weaver,
Blackhawk Management Group,Inc.
I get the impression he is either retired or doesn't want direct public involvement.
The USA --National Association of Music has a webpage where they cant get info on him ---a Dan Del Fiorentino of the above also has a webpage which if you fill in you can message him asking if he has found him.
Contact Dand | NAMM.org
Thanks for that info. It seems that Markley only sells strings now, so I'm not feeling optimistic that they will have a power trannie.
I am still looking for the schematic of the power supply for this amp. If I can see the transformer and rectified voltages, I can derive what is needed and maybe have someone build me a transformer to spec.
I am still looking for the schematic of the power supply for this amp. If I can see the transformer and rectified voltages, I can derive what is needed and maybe have someone build me a transformer to spec.
The Dean MArkley string company seems alive and well. A google search for Dean Markley COntact reveals an 800 number. I would call the string company and ask if they knew of anyone supporting the old amplifier line.
Also one of our members over at MEF used to work with Markley on amp design. Perhaps a post over there might get some assistance or direction from him.
Forums - Music Electronics Forum
Also one of our members over at MEF used to work with Markley on amp design. Perhaps a post over there might get some assistance or direction from him.
Forums - Music Electronics Forum
Although not the information on a T60 I have found a schematic of a DM
80-DR power amp .
Voltages are shown as 50V +/- and 15V +/- .
80-DR Power amp.jpg (JPEG Image, 1392 × 1075 pixels) – Scaled (87%)
There is also a guy selling DM schematics -----at $15 including the T60 but I don't know if it includes voltages -
Dean Markley Schematics
I really don't know much about DM other than time spent trying to trace him but he owned a music shop is said to have got guys in to design his circuits --- I have no idea whether that is true or not but there is a bit of controversy over it naming some other people .
Anyway maybe contact this guy ?-
Ask Amp Man: Dean Markley Signature Series Amps | Premier Guitar
here also is a rough schematic with the "very similar to the T60 & T120" --no voltages but the smoothing caps are rated at 450V DC working--click on link by "Mozwell " .-
Dean Markley CD 60 Original Amp Switching Schematic. - freestompboxes.org
Please also read the posts on this forum as one post says that Spectra SS & tube amps was sold to DM -
NAD - JMF Spectra 30T | Telecaster Guitar Forum
80-DR power amp .
Voltages are shown as 50V +/- and 15V +/- .
80-DR Power amp.jpg (JPEG Image, 1392 × 1075 pixels) – Scaled (87%)
There is also a guy selling DM schematics -----at $15 including the T60 but I don't know if it includes voltages -
Dean Markley Schematics
I really don't know much about DM other than time spent trying to trace him but he owned a music shop is said to have got guys in to design his circuits --- I have no idea whether that is true or not but there is a bit of controversy over it naming some other people .
Anyway maybe contact this guy ?-
Ask Amp Man: Dean Markley Signature Series Amps | Premier Guitar
here also is a rough schematic with the "very similar to the T60 & T120" --no voltages but the smoothing caps are rated at 450V DC working--click on link by "Mozwell " .-
Dean Markley CD 60 Original Amp Switching Schematic. - freestompboxes.org
Please also read the posts on this forum as one post says that Spectra SS & tube amps was sold to DM -
NAD - JMF Spectra 30T | Telecaster Guitar Forum
Have a read of the first post it names the DM design engineers in the first post particularly BK Butler who has a schematic somewhere on the web saying --
although its marked DM its designed by BK Butler -
JMF Amps Owners Club | Telecaster Guitar Forum
although its marked DM its designed by BK Butler -
JMF Amps Owners Club | Telecaster Guitar Forum
It might help to keep in mind we are not trying to contact Dean himself, we are trying to find support for the amplifiers that were made in his name.
All of the schematics linked above show different transformers. The first one is a low voltage solid state unit. The tube unit shown as similar to T60 is close, but the T60 has an additional winding whose voltage is unknown. Darned printed circuit board makes it impossible to tell what it powers without removing the PCB and tracing where each trace ends up.
All in all, it looks like a custom retrofit is needed.
All in all, it looks like a custom retrofit is needed.