DIY thoughts of the day

A place for DIY project discussions.
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karatestu
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Re: DIY thoughts of the day

Unread post by karatestu »

Did some work on my six channel integrated amp with nva amp boards and remote psu's (twelve of the buggers). First diy I have done since this bloody virus started. The psu's are going to be housed on the bottom level of my sound system "sideboard " in order to get them as far away from everything else as possible. Plus this level weighs an absolute ton and will help to keep the centre of gravity low.

Just above the psu's I am going to place a cast iron manhole cover to try and soak up some emi. Overkill ? Maybe but easy to try.

I need to get this amplifier section done as I can't listen to my diy speakers without. The earthing arrangement is proving to be a bit of a chin stroking affair. I don't want to go down the star earthing route as Doc will send me lightening bolts if i do. I found an internal pic of an AP80 which I am going to copy and just add more psu's and amp boards to the 0V bus bar .

It will either be amazing or end in fireworks.
DIY inspired by Richard "The Doc" Dunn RIP

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Fretless
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Re: DIY thoughts of the day

Unread post by Fretless »

Maybe Colin W. can give you some hints - he's another fan of the 'sounds amazing or blows up' approach. :grin:
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karatestu (Sun Jul 05, 2020 11:15 am)
NVA: P50sa-A40-LS6-Cube2-BMU
Interconnect cables: DH Labs Air Matrix
Digits: Intel Core i7 fanless silent PC + Volumio
USB: Oehlbach XXL Masterclock + DH Labs Mirage
DAC: TeraDak 4.5 Chameleon CD: Cambridge CXC
Ethernet: Silent Angel Bonn N8 + AQ Cinnamon
Cans: AQ NightHawk / NightOwl Carbon

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karatestu
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Re: DIY thoughts of the day

Unread post by karatestu »

Maybe I should do the big switch on with a broom handle on bonfire night :grin:
DIY inspired by Richard "The Doc" Dunn RIP

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Fretless
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Re: DIY thoughts of the day

Unread post by Fretless »

Is Donald Trump still looking for pyrotechnics to use at his next rally?
NVA: P50sa-A40-LS6-Cube2-BMU
Interconnect cables: DH Labs Air Matrix
Digits: Intel Core i7 fanless silent PC + Volumio
USB: Oehlbach XXL Masterclock + DH Labs Mirage
DAC: TeraDak 4.5 Chameleon CD: Cambridge CXC
Ethernet: Silent Angel Bonn N8 + AQ Cinnamon
Cans: AQ NightHawk / NightOwl Carbon

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karatestu
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Re: DIY thoughts of the day

Unread post by karatestu »

I must take a pic of a massive EI transformer i acquired (free). I have never seen one so big apart from the one up a pole 30 metres from my house. God knows how many VA it is. There are two windings- one centre tapped and one not. Haven't measured the voltages yet so don't know what I will use it for.

Perhaps a stereo amp using some old Avondale boards that I removed the input coupling cap, output zobel and output inductor & parallel damping resistor. They need converting from quasi complimentary to complimentary. Plus a few more components removed :dance: and a couple changed for different values
DIY inspired by Richard "The Doc" Dunn RIP

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Re: DIY thoughts of the day

Unread post by Latteman »

I’ll just leave this here for u Stu

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Analogue Source - DIY turntable- donor Thorens TD321, DIY Single pivot Carbon Tonearm; Grado Reference Platinum FL; Nva Phono 1 (160va);
Lenco GL59, G101 tonearm, Ortofon MC10/MCA10 Yaqin M23B (Les Box)
Digital Sources- Linn Mimik, iPhone 6s (base adapter)
Amplification KHOZMO Acoustic Passive Pre - & Nva A20LE (👍🏼)
Speakers- Diy ‘Isobaric Cubes’; Ls6 bi-wired
Dc blocker to mini BMU

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karatestu
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Re: DIY thoughts of the day

Unread post by karatestu »

Ohm speakers :happy-jumpeveryone:

Are they yours Peter ?

I read on diyaudio about magnet out speakers and that there were disturbances in the force (use the force Luke) due to the chassis diffracting the sound waves. Could be a load of old bollox for all i know without doing some flawed measurements. :lol:
DIY inspired by Richard "The Doc" Dunn RIP

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Re: DIY thoughts of the day

Unread post by Latteman »

No not mine

Quick question to all- why did Doc use 3 core mains cable when the earth wire is not connected at the amp end?
Analogue Source - DIY turntable- donor Thorens TD321, DIY Single pivot Carbon Tonearm; Grado Reference Platinum FL; Nva Phono 1 (160va);
Lenco GL59, G101 tonearm, Ortofon MC10/MCA10 Yaqin M23B (Les Box)
Digital Sources- Linn Mimik, iPhone 6s (base adapter)
Amplification KHOZMO Acoustic Passive Pre - & Nva A20LE (👍🏼)
Speakers- Diy ‘Isobaric Cubes’; Ls6 bi-wired
Dc blocker to mini BMU

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karatestu
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Re: DIY thoughts of the day

Unread post by karatestu »

I guess it is to protect you in case you cut the cable. Hopefully whatever you cut the cable with will also cut into the earth wire and the current will go to ground through that rather than you.

Just a guess :think: Tomasz will know for sure.
DIY inspired by Richard "The Doc" Dunn RIP

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karatestu
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Re: DIY thoughts of the day

Unread post by karatestu »

Going back to those ohm speakers, mounting the tweeter like they have done is probably to time align it with the centre of the up firing magnet out mid bass. There must be some strange diffraction going on there but in the grand scheme of things maybe it is not worth worrying about.

You can't time align the two drivers in a cube type speaker unless you do as the ohm speakers have or delay the signal :naughty: going to the front mounted tweeter. Doc obviously thought it was not worth worrying about.

With my speakers I need all the cabinet volume I can get my hands on so doing it the ohm way would make the tweeter too far above seated listening level. All the same I can't help wondering how it would sound with four tweeters (firing front, back & to both sides) sandwiched between the two magnets of my upfiring 12" and down firing 5" :think:

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DIY inspired by Richard "The Doc" Dunn RIP

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