Dieselpunk Preamp of Doom and the Beast with Two Backs

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

Post by Thermionic Idler »

Here's a pic of the delta 1 and delta 2 boards - they are complete except for the inter-board pin connectors which require referral to the (currently offline) documentation:

Image

The four of these will stack vertically. The two boards on the left are the relay stepped attenuator, the two on the right are the input / output switching boards. Both use telecoms grade relays to do the switching.

On the floor behind me is a box containing various handy things to have when building stuff - various sizes of heat-shrinking, cable ties and other spares type junk that I've just thrown together.

Unfortunately.....

Image

This presents me with a conundrum cos usually, building has to be snuck in during periods when the cat is asleep, otherwise he has a habit of jumping up onto the desk and saying "hey, what ya doing, is that some really precise and delicate soldering you're doing there? I bet I can help..."
Deck: Garrard 301 - Audio Origami PU7 - NW Analogue DH3S
Phono: Pete Millett LR, Lundahl SUT, AMB σ22 PSU
Linestage: Bruno Putzeys Balanced Pre + Hans Polak relay mod, LCDuino control
Power amps: 300B PP 'Symmetric Reichert'
Speakers: FF225WK Big Mets
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Ray P
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#122 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Ray P »

Thermionic Idler wrote: Fri Oct 20, 2017 6:22 pmThis presents me with a conundrum cos usually, building has to be snuck in during periods when the cat is asleep, otherwise he has a habit of jumping up onto the desk and saying "hey, what ya doing, is that some really precise and delicate soldering you're doing there? I bet I can help..."
I have a similar workshop assistant. Her timing is impeccable - just when I'm set to perform the most fiddly job is when she'll choose to jump onto my lap to seemingly inspect/check that I'm doing it right.

Another of her part tricks is to go through the laundry basket - we'll often come home to find that she has selected socks and deposited them around the house. Funny thing is that is only particular socks and she ignores the rest.
Sorry, I couldn't resist!
SteveH
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#123 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by SteveH »

AMB website is back up.
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Thermionic Idler
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#124 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler »

SteveH wrote: Sat Oct 21, 2017 12:13 am AMB website is back up.
Thanks for letting me know Steve.

As a result I was able to populate the top side of the logic board this morning - this is the brain of the whole thing:

Image
Deck: Garrard 301 - Audio Origami PU7 - NW Analogue DH3S
Phono: Pete Millett LR, Lundahl SUT, AMB σ22 PSU
Linestage: Bruno Putzeys Balanced Pre + Hans Polak relay mod, LCDuino control
Power amps: 300B PP 'Symmetric Reichert'
Speakers: FF225WK Big Mets
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#125 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Mike H »

Is it not possible to save off the information?
 
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#126 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by jack »

Been looking at the AMB site - nice!
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Thermionic Idler
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#127 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler »

jack wrote: Sun Oct 22, 2017 12:27 pm Been looking at the AMB site - nice!
Yes he has some quite toothsome stuff there. The A24 linestage circuit is also used as the output stage in the top end Gamma 3 DAC, the only difference being that a low pass filter is implemented for the DAC (the linestage is wide open to 1 Mhz).
Deck: Garrard 301 - Audio Origami PU7 - NW Analogue DH3S
Phono: Pete Millett LR, Lundahl SUT, AMB σ22 PSU
Linestage: Bruno Putzeys Balanced Pre + Hans Polak relay mod, LCDuino control
Power amps: 300B PP 'Symmetric Reichert'
Speakers: FF225WK Big Mets
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Thermionic Idler
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#128 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler »

Well, dressing this lot was fun.....

Image

Power supply boards wired up to AC.
Deck: Garrard 301 - Audio Origami PU7 - NW Analogue DH3S
Phono: Pete Millett LR, Lundahl SUT, AMB σ22 PSU
Linestage: Bruno Putzeys Balanced Pre + Hans Polak relay mod, LCDuino control
Power amps: 300B PP 'Symmetric Reichert'
Speakers: FF225WK Big Mets
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Thermionic Idler
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#129 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler »

Input / output socket wiring installed with Molex connectors, ready to interface to the I/O / attenuator relay stack. Not one of my favourite jobs!

To the right are two tools that probably saved me a significant amount of time and bother. A molex terminal crimper (though not the official Molex one as they charge a feckin' fortune for it - this one is a ratcheting device from a UK seller on eBay for about £21 I think, superior to the really cheap ones on Ali Express and as far as I could see did just as good a job as the £200+ Molex tool). The other thing is a set of wire twisting pliers I got from Machine Mart.

Image
Deck: Garrard 301 - Audio Origami PU7 - NW Analogue DH3S
Phono: Pete Millett LR, Lundahl SUT, AMB σ22 PSU
Linestage: Bruno Putzeys Balanced Pre + Hans Polak relay mod, LCDuino control
Power amps: 300B PP 'Symmetric Reichert'
Speakers: FF225WK Big Mets
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Thermionic Idler
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#130 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler »

We're done! Well, almost, I have to fit the IC's into the delta boards and then start all the various power-up tests - so I have no idea at this point whether it's all going to work! :shock:

Time for a little break I think...

Image

Image
Deck: Garrard 301 - Audio Origami PU7 - NW Analogue DH3S
Phono: Pete Millett LR, Lundahl SUT, AMB σ22 PSU
Linestage: Bruno Putzeys Balanced Pre + Hans Polak relay mod, LCDuino control
Power amps: 300B PP 'Symmetric Reichert'
Speakers: FF225WK Big Mets
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#131 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by IslandPink »

Haven't you missed out the valves ?
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#132 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Cressy Snr »

That is looking mighty fine Dave! :D
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#133 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Mike H »

Yep. :thumbleft:
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
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Thermionic Idler
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#134 Re: Dieselpunk Preamp of Doom and the Beast with Two Backs

Post by Thermionic Idler »

It's alive!! :D

Image

So far:

- all power supplies measure up perfectly
- it's successfully learned all the remote control commands
- the first I/O board of relays checks out OK.

Now to add more delta boards and continue testing.
Deck: Garrard 301 - Audio Origami PU7 - NW Analogue DH3S
Phono: Pete Millett LR, Lundahl SUT, AMB σ22 PSU
Linestage: Bruno Putzeys Balanced Pre + Hans Polak relay mod, LCDuino control
Power amps: 300B PP 'Symmetric Reichert'
Speakers: FF225WK Big Mets
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Thermionic Idler
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Location: Southsea

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

Post by Thermionic Idler »

Testing complete and it appears to be working perfectly! So far only used with unbalanced inputs / outputs but first impressions are extremely good - crystal clear, pretty damn close to a straight piece of wire with gain which is what you want an active linestage to be.

Photograph taken in the rack - I've tried, and failed, to capture what the VU meters look like backlit with proper incandescent bulbs - just like a 1930's wireless. I'll need to take another in the daylight, I think.

Image
Deck: Garrard 301 - Audio Origami PU7 - NW Analogue DH3S
Phono: Pete Millett LR, Lundahl SUT, AMB σ22 PSU
Linestage: Bruno Putzeys Balanced Pre + Hans Polak relay mod, LCDuino control
Power amps: 300B PP 'Symmetric Reichert'
Speakers: FF225WK Big Mets
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