Another DIY SS Amplifier with NVA Boards

A place for DIY project discussions.
Forum rules
1. No ad-hominem
2. No spamming or shilling
User avatar
SteveTheShadow
Posts: 944
Joined: Thu Sep 12, 2013 5:24 pm
Location: S Yorks
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 4:24 pm

Everything in my system is referenced to earth. I'm used to extreme safety measures given the high voltages I usually play with.
We'll see if there is any hum once I get it in the system.
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Sealed cabs with Fane 12-250-TC 12" full range drivers. Also, Winslow Burhoe/Roy Allison/Richard Dunn influenced semi-omnidirectional.

User avatar
Dr Bunsen Honeydew
Posts: 28536
Joined: Wed Jul 11, 2012 7:26 pm
Location: Muppet Labs
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by Dr Bunsen Honeydew » Sat Mar 10, 2018 4:27 pm

How thick is that base plate, it seems to me you are under heatsinked.

User avatar
SteveTheShadow
Posts: 944
Joined: Thu Sep 12, 2013 5:24 pm
Location: S Yorks
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 4:32 pm

4mm
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Sealed cabs with Fane 12-250-TC 12" full range drivers. Also, Winslow Burhoe/Roy Allison/Richard Dunn influenced semi-omnidirectional.

User avatar
SteveTheShadow
Posts: 944
Joined: Thu Sep 12, 2013 5:24 pm
Location: S Yorks
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 4:37 pm

It's all working and is currently soaking on test.
Image

Gentle hiss with ear to each speaker.

Devices only slightly warm to the touch, although it is of course only idling.
Mains transformer very quiet.

I'll try it on some music shortly.
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Sealed cabs with Fane 12-250-TC 12" full range drivers. Also, Winslow Burhoe/Roy Allison/Richard Dunn influenced semi-omnidirectional.

User avatar
Dr Bunsen Honeydew
Posts: 28536
Joined: Wed Jul 11, 2012 7:26 pm
Location: Muppet Labs
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by Dr Bunsen Honeydew » Sat Mar 10, 2018 4:39 pm

You are under heatsinked for that voltage. No problem normally but 4 ohm or difficult loads and played loud then it will get very hot, maybe too hot. For you if it is just your speakers just keep an eye (hand) on temp. For a production unit I would have used a proper heatsink not just a plate, unless bloody enormous like Stu's one.

Smaller voltage less VA as with the A20 then a plate is fine.

User avatar
SteveTheShadow
Posts: 944
Joined: Thu Sep 12, 2013 5:24 pm
Location: S Yorks
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 4:52 pm

Thanks Richard.
I'm only intending to use it as a low power amp like the A20. I'm only using 25V secondaries as I wasn't in the end, prepared to fork out for transformers until I was sure I wasn't going to blow the things up so I used a toroid I found in one of my boxes. I did however fork out for a nice case; a case of arse about face priorities maybe? - go figure :lol:

Now I know what I'm doing (sort of) I could easily up the power, monoblock it and put it in a pair of whacking great heatsinked cases. A new set of output devices and boom! (not literally I hope)
Last edited by SteveTheShadow on Sat Mar 10, 2018 4:56 pm, edited 1 time in total.
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Sealed cabs with Fane 12-250-TC 12" full range drivers. Also, Winslow Burhoe/Roy Allison/Richard Dunn influenced semi-omnidirectional.

User avatar
Dr Bunsen Honeydew
Posts: 28536
Joined: Wed Jul 11, 2012 7:26 pm
Location: Muppet Labs
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by Dr Bunsen Honeydew » Sat Mar 10, 2018 4:56 pm

Maestro - music please!

User avatar
SteveTheShadow
Posts: 944
Joined: Thu Sep 12, 2013 5:24 pm
Location: S Yorks
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 5:01 pm

Dr Bunsen Honeydew wrote:
Sat Mar 10, 2018 4:56 pm
Maestro - music please!
There you go.
Image

Been going for about 15mins
Bloody hell, this is good 8-)
I'll run it up for an hour and check the devices' temperatures
Once that's done, I just need an LED and resistor fitting and the front panel and top plate.

Review later.
Last edited by SteveTheShadow on Sat Mar 10, 2018 5:14 pm, edited 1 time in total.
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Sealed cabs with Fane 12-250-TC 12" full range drivers. Also, Winslow Burhoe/Roy Allison/Richard Dunn influenced semi-omnidirectional.

User avatar
karatestu
Posts: 1209
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by karatestu » Sat Mar 10, 2018 5:10 pm

Nice one Steve :guiness;

I bet i know what you will be doing tonight :dance:
Naim, Linn & Harbeth fanboy

User avatar
SteveTheShadow
Posts: 944
Joined: Thu Sep 12, 2013 5:24 pm
Location: S Yorks
Great Britain

Re: Another DIY SS Amplifier with NVA Boards

Unread post by SteveTheShadow » Sat Mar 10, 2018 5:57 pm

Aye, there'll be a bit of listening and appreciating.

Finished job, complete with LED indicator:
Image

That was fun. I'm doing the snapbackjack, stimulator, alligator! :dance:
DIY NVA amplification ( roughly equivalent to NVA A60) BTE Designs passive preamp, BTE Designs Lenco L75 turntable, Rega R200 arm, Goldring E3 cartridge, NVA Phono 1
Musical Fidelity M1 DAC, AppleTV4 with Apple Music subscription, ripped CDs streamed via WD MyCloud Home Duo NAS, with PLEX media server.
Speakers - Sealed cabs with Fane 12-250-TC 12" full range drivers. Also, Winslow Burhoe/Roy Allison/Richard Dunn influenced semi-omnidirectional.

Post Reply