Dieselpunk Preamp of Doom and the Beast with Two Backs

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jack
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by jack » Tue Dec 19, 2017 10:50 am

Ray P wrote:
Mon Dec 18, 2017 9:43 pm
Hi Dave, I dunno whether this will inspire you or distract you but this is a pretty neat Beast project...

http://sharksphotos.yolasite.com/
Nice amp - whilst looking at the transformer covers - obviously cut by laser or a profile cutter - I was thinking of the Shaper Origin - sort of thing that would make that so much easier... (at a cost).

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Thermionic Idler
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler » Tue Dec 19, 2017 11:19 am

Came across a particularly evil bug in my CAD software yesterday - you're always told to save your work regularly and I do that as a matter of course, as the software is a little bit 'crashy' - especially as my version is several years old and I'm too tight / poor to upgrade to the latest. It does the job fine.

Last night, it rather charmingly decided to crash in the middle of a save - thereby completely corrupting the file and rendering it unrecoverable.

Luckily, because of a lot of recent significant changes, I've been incrementing the versions. I had in fact incremented an hour previously so I didn't lose too much work, but heck! :shock: The preamp design stayed at version 5.0 for quite some time and if that bug had surfaced with that file, we might not have a preamp in the rack right now. (I save to a drop box folder which auto-syncs to the cloud).

From now on I do "Save As..." and up the version number each time! I put this here as a cautionary tale for anyone doing similar work.
Deck: Garrard 301
Audio Origami PU7
Van Den Hul Black Beauty
Phono: Whest PS30RDT
Pre-amp - Scratch built AMB α24/LCDuino
Amp - Transcendent "Son of Beast" 15W OTL
Speakers - FF225WK Metronomes

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Mike H
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Mike H » Tue Dec 19, 2017 1:49 pm

One word - "backups". :D

I have even saved a file with a changed name, just so the previous is a backup. But you've already figured that out.

Another method I sometimes use is have a sub-folder called "Backup", and put copies of files in there.


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Thermionic Idler
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler » Sun Dec 24, 2017 3:33 pm

The CAD work for the Beasts is nearing completion, I just have to 'mirror image' the housing bracket layout and it'll be about done.

Here is how the mirror imaged pair are expected to look:

Image
Deck: Garrard 301
Audio Origami PU7
Van Den Hul Black Beauty
Phono: Whest PS30RDT
Pre-amp - Scratch built AMB α24/LCDuino
Amp - Transcendent "Son of Beast" 15W OTL
Speakers - FF225WK Metronomes

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Thermionic Idler
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler » Fri Jan 12, 2018 3:44 pm

Construction of the two monoblocks will require the fabrication of 18(!) panels in total. I have finished building the FPD (front panel designer) files for the first 16, outstanding are the two cream coloured top panels (where the valve sockets and transformers etc sit) with the 5mm inner diameter bend, that Schaeffer are going to do for me.

I added up the pricing just for those first sixteen and had to go and lie down in a darkened room! :shock:

I'm still trying to get out of Schaeffer what the bending allowance / K-factor figure is for the bend, so that I can plug it into CAD and generate an accurate map for the CNC machine. I sent them an email asking for this along with a CAD drawing of the bent panel so they'd have a picture of what I wanted - so far they've quoted me a cost including transferring the data from that CAD file to an FPD file - which I am perfectly capable of doing myself, all I need to know is the bending allowance!! Here's hoping I get the right answer soon....
Deck: Garrard 301
Audio Origami PU7
Van Den Hul Black Beauty
Phono: Whest PS30RDT
Pre-amp - Scratch built AMB α24/LCDuino
Amp - Transcendent "Son of Beast" 15W OTL
Speakers - FF225WK Metronomes

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ed
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by ed » Fri Jan 12, 2018 4:17 pm

Thermionic Idler wrote:
Fri Jan 12, 2018 3:44 pm

I added up the pricing just for those first sixteen and had to go and lie down in a darkened room! :shock:
I still think my posts around 2nd August are relevant. It would really pay to find a chap with a bending press.....
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by IslandPink » Fri Jan 12, 2018 4:23 pm

I got a local specialist in this sort of work to fabricate me the housing for the Pass F4 from 2.5mm aluminium. That cost about £200.
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by ed » Fri Jan 12, 2018 5:58 pm

I got a local specialist in this sort of work to fabricate me the housing for the Pass F4 from 2.5mm aluminium. That cost about £200.


wowsa, I must just be lucky then........So far the F2,F4,F6,zen5 have cost me £20 in total for all the bottoms and backs. The fronts have all been 5mm offcuts and the tops I cut out of a full sheet of 50% 6mm perf 2mm thick, which I think cost about £50 delivered from ebay. So that's about £70 for 4 chassis.This obviously does not include the heatsinks or the 25mm equal angle...but, but....

These obviously won't look as shoddy as Mr Idler's and they are in bare aluminium finish....but I still think it's worth looking around for alternative methods......yeah, I know, I'm a cheapskate..
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by IslandPink » Fri Jan 12, 2018 6:20 pm

I wasn't trying to compete with you, Ed - I know better - as you're in Hull !
However I'll pick you up on counting offcuts as cost-free - that's cheating ! ( unless you found them in a skip )
I was overcharged for that chassis, just interested in what the number was that put Dave in a darkened room.
"It's so easy to decide on a name
It's a name caller's game
It's so easy to look down from above " (Wyatt)

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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by ed » Fri Jan 12, 2018 7:21 pm

IslandPink wrote:
Fri Jan 12, 2018 6:20 pm
I wasn't trying to compete with you, Ed - I know better - as you're in Hull !
good point, well made!

I'm still working on the escape plan
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler » Sat Jan 13, 2018 12:13 am

IslandPink wrote:
Fri Jan 12, 2018 6:20 pm
I was overcharged for that chassis, just interested in what the number was that put Dave in a darkened room.
I think for now I'll just say "a lot". I think it'll be worth it though. These things are going to be in the living room next to each speaker - they have to look good as well as sound good.
Deck: Garrard 301
Audio Origami PU7
Van Den Hul Black Beauty
Phono: Whest PS30RDT
Pre-amp - Scratch built AMB α24/LCDuino
Amp - Transcendent "Son of Beast" 15W OTL
Speakers - FF225WK Metronomes

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Thermionic Idler
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler » Fri Jan 19, 2018 11:09 pm

Hooray - I finally got a number for the bending allowance. Now I can generate the remaining two FPD files and get a final cost...
Deck: Garrard 301
Audio Origami PU7
Van Den Hul Black Beauty
Phono: Whest PS30RDT
Pre-amp - Scratch built AMB α24/LCDuino
Amp - Transcendent "Son of Beast" 15W OTL
Speakers - FF225WK Metronomes

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Thermionic Idler
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler » Mon Mar 05, 2018 2:04 pm

Slow progress of late but last week whilst snowed in, I worked on populating the main circuit boards.

Electrolytics are mostly high temp Panasonics, all fast recovery diodes (UF4007, FR605-T), 2W resistors are Vishay CPF series metal films rather than metal oxide, 0.5W are Takman metal films aside from a couple of positions where the specified value was unavailable, these have Vishay CMF's instead.

I have the signal coupling caps, T4 transformer and big smoothing caps left to populate. Hit a snag yesterday, I had bought ClarityCap ESA's to go in the C13, C14, C17 and C18 positions. Unfortunately, I discovered two problems: 1) the leadouts on the 0.47uF cap were 1mm solid core, which was just that little bit too big to go through the PCB hole. That could probably have been kludged around but 2) checking the ESA datasheets revealed they were only rated to 70C, and I wanted everything in here to be rated to at least 100C for long life.

I've emailed HiFi Collective to see if I can exchange them for AMCO Amtrans caps as they cost about the same, are rated to 100C and will fit perfectly into the available PCB space. I already have one in the C16 position (on the cathode of the positive 12BH7 driver valve), next to Z6. Just hoping the 20% tolerance on these won't be a problem (I don't think it will be).

Image
Deck: Garrard 301
Audio Origami PU7
Van Den Hul Black Beauty
Phono: Whest PS30RDT
Pre-amp - Scratch built AMB α24/LCDuino
Amp - Transcendent "Son of Beast" 15W OTL
Speakers - FF225WK Metronomes

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Nick
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Nick » Mon Mar 05, 2018 3:27 pm

Do you expect the inside to get above 70C ?
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Thermionic Idler
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Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler » Mon Mar 05, 2018 4:29 pm

Nick wrote:
Mon Mar 05, 2018 3:27 pm
Do you expect the inside to get above 70C ?
It shouldn't get that high, at a guess maybe mid 50's at the very most on a hot day? The idle heat should be about 240 watts a side with a 12 tube configuration (it can be reduced to 8 tube / 175 watts in the summer). It's more that I wanted to ensure a good wide margin between the rated and actual running temperatures so that the components would last longer. Probably overkill, but I'm all about the over-engineering! :D
Deck: Garrard 301
Audio Origami PU7
Van Den Hul Black Beauty
Phono: Whest PS30RDT
Pre-amp - Scratch built AMB α24/LCDuino
Amp - Transcendent "Son of Beast" 15W OTL
Speakers - FF225WK Metronomes

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