Hi all, been reading posts on here for a few years on and off as I've considered building some electronics... about 2 years ago I finished my power amp based on Project 101 by Rod Elliott. Currently working on a pre-amp to go with it that's based on Doug Self's circuits, I'll post photos later if anyone is interested. Any questions or suggestions fire away!
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Hi. Thanks. Yes they're DIY, I used a method using alternating pieces of 2mm flat plate and 6mm bar all pulled together using threaded rod after seeing the idea on Rod Elliott's website. I just varied the sizes of the plates to make the curved shape. May have overdone it as they're very heavy which necessitated a strong baseplate and other panels. The whole thing weighs about 35kg!
This is my preamp aka 'the beast' that I'm working on. It is based on the Elektor preamp 2012 but with modifications to the tone controls I found in Doug Self's Small Signal Audio Design book. I've also added a headphone amplifier. I'm also using switched attenuators (using relays) instead of pots for the volume and tone controls. The phono stage is in the flashy copper box 
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Thankyou. I like the sound very much. Turning it on and listening to it for the first time was a nervous experience given the time and money spent! I haven't bought hugely expensive equipment in the past so don't have a 'benchmark' so to speak. I did have a Jungson JA88D amp for a couple of years which sounded possibly more transparent but I was using a different and possibly better DAC at the time. The treble/top end sounds better in my opinion on the P101 than the Jungson, having a bit more 'air' as it's called. I've recently upped the bias to 100mA (using +/-55V rails and two output pairs) and am currently seeing if and how that may improve things.
Awesome build there. How did you do all the front/rear panel lettering? Looks so professional...
Thanks. Lettering on the back was done using a vinyl label printer where I work. It also cuts which helps a lot. The lettering on the front was engraved using a bench top CNC I have access to at work. The majority of the build was done by hand though. I used a woodworking router to shape some of the panels. I've just had to replace the bearing
Oh and the lettering on the meter scale was done by sending a jpeg off to an online label printing service.
Nylon bolts through the transformers... Nice.This is my preamp aka 'the beast' that I'm working on. It is based on the Elektor preamp 2012 but with modifications to the tone controls I found in Doug Self's Small Signal Audio Design book. I've also added a headphone amplifier. I'm also using switched attenuators (using relays) instead of pots for the volume and tone controls. The phono stage is in the flashy copper box
Yes, they were steel originally but the transformers were a bit closer to the PCB than I would have liked and I ended up making a kind of shielding can to go over them. Nylon bolts so as not to cause a shorted turn. I used nylon bolts horizontally to hold the transformers in my power amp to prevent a shorted turn (due to the way they're mounted). In the power amp I also think they may dampen any hum/vibration (the centres are potted).
Lovely hand machined face. Have you thought of how to satin brush it? You can sand blast and the use etching fluid to eat the rough out of it. It would seem that you have a separate regulator for everything. Impressive. The chassis is nicely lay out and symmetrical. Never hear of that pre-amp module, could be interesting since all connectors and mounted on in and obviously floating from the chassis. The earth bar is nice but since you spent so much, it could have been solid copper "very high endThis is my preamp aka 'the beast' that I'm working on. It is based on the Elektor preamp 2012 but with modifications to the tone controls I found in Doug Self's Small Signal Audio Design book. I've also added a headphone amplifier. I'm also using switched attenuators (using relays) instead of pots for the volume and tone controls. The phono stage is in the flashy copper box
". Carefully looked over your solder joints, I could see, and your soldering skills are great. Wondered why there was a floating screen, did you find a ground loop? Beautiful choice of knobs, resembles those of an old Luxman , try to get a similar finish on the fascia. Remember a little felt washer under the knobs, it would be very professional and smooth operating, as well as hide any flaws in the holes that might be visible. I have build and designed literally thousands of amp prototypes in my lifetime, and your work is "world-class". You are moving rapidly to the work of Bonzai, one of my favourite designers, ranking with and even exceeding Nelson Pass. In many cases, both aesthetically, functionally and quality. He could give you many hints (I won't name-drop just in case he objects. I have been here only today after almost 2 years of absence. I trust that it sounds as good to you as you wanted it, with the sound signature you desired. Have a great life! Divulging specs is totally unimportant, it has nothing to do with sound signature, stuff with perfect specs normally sound terrible and only appeal to the owner, design to a basic spec, measure and listen a lot. You may alter any sound and the final product would be exactly to your sonic expectation, bragging rights is only for the audiophile idiots not for true Listers and music lovers. If you have ever seen what happens in a recording studio, it makes you wonder how you could ever have listened to some crap available. Having to then only buy audiophile recordings is expensive and wasteful. Actually, having a too revealing amp could make all your super loved tracks sound like crap, then you have to mess around with all kinds of brands of headphone/speakers to try and correct it to be listenable and half enjoyable "more unnecessary expense". Room treatment is a total waste of money - tone controls are absolutely necessary as you have included in your design. Kindly drop a sample of your library recorded directly from your amp on the forum. I would love to hear it through one of my systems. Sorry, I forgot Mooley, and excellent resource and vault of knowledge, practical and theoretical - mostly spot on with his comments and extremely helpful, always good to refer to his posts. I will not pay too much attention to the young mavericks on the forum, reason why I lost total interest besides they mostly try and tear your design that sounds magnificent to you apart and super annoying, try not to post any detail on the forum, I would recommend direct mail to Mooly or Bonzai. Avoid the PASS forum, there are one or two know it alls that could really annoy you. This product you designed IS for your pleasure, no one else.