A new thread for general DIY discusion, impressions and thoughs.
A few ground rules:
99% of the time there is no right way to achieve a certain goal
comparing schematics, builds and components idealy should be from personal experience
IMO(in my opinion) should be the default position and everyone can make up their own mind. For example, IMO the last 300B filter caps in the WA5 are cheap generic electrolitics and have no place for such a price point. Common sense would dictate this is the place for the best quality cap.
A separate chassies in theorey sounds great, in practice the ombilical cable is a royal pain, was shoked when I found quality connectors are over $100, including a quality cable or even worse a dual solution for high and low voltage the price skyrockts.
That’s what I’ve done for the prototype of my DIY amp, an open separate PSU I can easitly work on.
Now to go with the recommended solution for an ultimate tube amp, separate heater transformer per tube with a choke, a well filtered split power supply decoupled per channel, a dual PSU chassies might be needed.
Once I got all the parts for the upgraded PSU I realised there’s no way I can put everything in a single unit. To the above photo I have to cram this: 16 transformers total. The price for a no compromise build
Good stuff. Theory vs practice. No compromises for the ultimate. There are some pursuits that make sense for DIY and one’s own enjoyment, but may not from a commercial/business perspective. Looking forward to tracking this thread.
Very happy this thread was made. I have been doing research on starting to build my own tube amps. I love that there will be a thread to come back to, to post resources, guides, what I have found, and builds as they are coming along. Glad to have experienced people in DIY tube amps such as @M17XR2B.
Finished the chassis work for a new PSU, wiring will follow. God only knows why I need a 6th amp but the calling is too strong to ignore.
Scored a great vintage oil impregnated C core mains transformer and choke for input. The DHTs filaments will be choke input as well. HV PSU will be: 300-0-300 -> 10H -> 70uF -> split -> 10H -> 70uF, all film and will give the 4 lead clarity cap TC a go. May add another smaller MR as a reservoir in the main chassis. 15kg just the PSU. The filament and rectifier transformers are custom ordered from ETE in the UK. 9 pieces of iron total.
I would be interested to see once you have the wiring done, I like to trace things even though I have limited knowledge of the intricate details of tube amp components.
That is a beast of an amp. Im trying to scale it with the Stellaris in the background.
Interesting article, tho sand in the signal path is always bad isn’t really true, it just has to be implemented properly. I love of the use of gyrators in the right place. For example a high Rp tube say 10K, a choke will never be practical and a CCS will most likely sound better.
That’s an example of an amp I don’t want to build 1000V+ is scary.
Pete Millett’s unnecessarily complex 300B was a profound inspiration for amp design and building, one can never be unnecessarily when the goal is overengineering. http://www.pmillett.com/uc300b.htm
I do believe you are correct about the Freya +, I have designed my own OTL amp so that I can get the tube sound I want, and may have to consider doing my own pre-amp one day. Nothing against the Freya of course. My only problem is everyone who has heard my amp wanted one and I am trying to wind down the build process lol.
And no, I have never been coached lol, it could help huh?
I am into version 2 right now and it has been described as having incredible highs, I needed to move up to Focal Utopias to really hear the sound.
What part of the country are you in? I occasionally send out loaners and I have given away seven but I need to stop doing that lol. They have to look pretty as well as sounding good.
Obviously you are a man of culture and taste. I always do splines on the amp cases. Think about a couple wood preferences so if I do send a sample and you like it, we are not shipping it back and forth getting you a cabinet you prefer. The wood in the above photo is nearly impossible to find, that is honey locust and it is not common, it is my personal amp now.
My current builds are matching amp and VU meter box in birdseye maple and ebony. I also have the usual, tiger maple, walnut, cherry etc. You would be under no obligation of course.
Very nice woodwork and incorporation of splines. The honey locust above looks quite special. All the woods you mention have appeal and I’d be grateful to sample/touch any. I I do like black walnut or red oak, and have an affinity to California Redwoods/Sequoias and Pacific Island woods such as koa.
Great connecting with you and having you be a part of the community!
I am doing a walnut amp for a gentleman right after I finish the work for FLTWS, I bought several pieces of black walnut and generally I let the recipient pick what he likes. I will do the same for you and it is a sample, it is as easy for me to build with one kind of wood compared to another. I am not as familiar with the woods you mentioned. I am in Indiana and we get a lot more oak, walnut, poplars etc.
Koa is lovely but finding large enough boards would appear to be an issue.
Thanks for sending. I had come across Torq’s review weeks ago, and it’s telling that he bought one for himself. I’ll have to re-read the article now that I have a better sense of what I’m looking for.
Oh, that’s a nice coincidence with the walnut. That’s very gracious of you and I’m excited. The woods I mentioned are pretty specific, more for an FYI, although Zach at ZMF has used koa for headphones.
