raketenmann
Active member
Dear community
A couple of years ago I acquired an old Miles Platting 100W guitar/bass head. What I didn't know is that the amp was heavily modified. So the amp needs a service which includes changing of the filter caps and probably even more since the amp is noisy and starts oscillating at some volume.
However, the amp has been modified so wildly and without safety standards so that I can't find a tech to lay hands on at a reasonable price. So I am in the situation to either dump the amp completely or just put a lot of effort into it and just rebuild it back to stock, which is what I tend to do at the moment.
However, I am not an electrician neither an engineer. I know some basic stuffs about amps, now where the dangers of filter caps are and I already built s small tube amp and some guitar pedals before. My plan would be to gather all the infromations I need to rebuild the stock circuit, do all the soldering, show it to a repairsmann who checks the power stage and then adjusts the Bias.
However, this means that there are a lot of open questions and I would really be thankful if there are some people that would be willing to share their thoughts and time to give me a little guidance through this.
So first things first: I am currently creating a bill of materials. Some of the original resistors and caps are probably still inside the amp. My question is: should I just dump all the old electonics and replace them or should I try to recycle some of the old parts? Based on what knowledge whould you make your decision? Also, If I am to replace resistors and caps: What are your suggestions about the materials to use?
I am lucky that I know an older man who has a tube tester and the old original tubes (Mullard EL34 and Brimar 12AX7) are still in working order with a lot of life left in them. The power transformer has been replaced, but the OT is still the original one.
Another question: this amp is soldered completely freely without a board. This makes it a lot more difficult for me as a Rookie to get it all together. So my question is: I know it would be possible to build the whole preamp section onto a turret board. But obviously I am not the guy to do so. Are there people that are able to do draw a board on the computer without too much effort and would be willing to do so? That would be so much help!
And while taking about preamp circuit: The amp offers two channels that are completely identical. Probably it would be fun to modify one of the two a little different.... any ideas?
Thanks a lot for all your help already!
PS: in the attachments you'll find all the shematics and a picture of the original amp inside and one of my modified example...
A couple of years ago I acquired an old Miles Platting 100W guitar/bass head. What I didn't know is that the amp was heavily modified. So the amp needs a service which includes changing of the filter caps and probably even more since the amp is noisy and starts oscillating at some volume.
However, the amp has been modified so wildly and without safety standards so that I can't find a tech to lay hands on at a reasonable price. So I am in the situation to either dump the amp completely or just put a lot of effort into it and just rebuild it back to stock, which is what I tend to do at the moment.
However, I am not an electrician neither an engineer. I know some basic stuffs about amps, now where the dangers of filter caps are and I already built s small tube amp and some guitar pedals before. My plan would be to gather all the infromations I need to rebuild the stock circuit, do all the soldering, show it to a repairsmann who checks the power stage and then adjusts the Bias.
However, this means that there are a lot of open questions and I would really be thankful if there are some people that would be willing to share their thoughts and time to give me a little guidance through this.
So first things first: I am currently creating a bill of materials. Some of the original resistors and caps are probably still inside the amp. My question is: should I just dump all the old electonics and replace them or should I try to recycle some of the old parts? Based on what knowledge whould you make your decision? Also, If I am to replace resistors and caps: What are your suggestions about the materials to use?
I am lucky that I know an older man who has a tube tester and the old original tubes (Mullard EL34 and Brimar 12AX7) are still in working order with a lot of life left in them. The power transformer has been replaced, but the OT is still the original one.
Another question: this amp is soldered completely freely without a board. This makes it a lot more difficult for me as a Rookie to get it all together. So my question is: I know it would be possible to build the whole preamp section onto a turret board. But obviously I am not the guy to do so. Are there people that are able to do draw a board on the computer without too much effort and would be willing to do so? That would be so much help!
And while taking about preamp circuit: The amp offers two channels that are completely identical. Probably it would be fun to modify one of the two a little different.... any ideas?
Thanks a lot for all your help already!
PS: in the attachments you'll find all the shematics and a picture of the original amp inside and one of my modified example...
