HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

Did my back in yesterday Bloody agony and the pain in my groin was unrelenting. Had to lay on the floor and only one position brought any relief at all. What's this got to do with diy ? Well I was moving my diy speakers to another wall in my office/ work room

A very hot bath, more laying on the floor with a hot water bottle and copious amounts of San Miguel did the trick and I went to bed in a much better state than I was in at 4pm that afternoon.

I got to listen to my speakers on a solid wall with no windows behind them. The walls are about 20" thick in that farm house (built 1725) so there is quite a volume in the window holes. I can't really say much as I was in agony and not in a mood to listen critically. Pain was making me feel delirious , nauseous, cold and with pins and needles in my hands. Them bloody speakers have a lot to answer for

Anyway the little that I can remember is that the sound presentation was altered to quite a large degree. I am not sure the rear firing tweeters are a good idea when firing at a wall only two inches away but we shall see. Previouly they were firing in to the window opening and about two feet from the glass. I am quite excited to hear the system again but when relaxed and not in a crumpled mess on the floor.

One of the things they don't tell you about recovering from a brain bleed is the relentless pain. It's neurological so there is nothing you can do. As your brain at last discovers youve got a right side.

You can try all kinds of pyscho active drugs, but they turn you into a zombie and may not work.

I've been in constant pain for about 18 months as my brain develops new connections and tries to move my right side.

So as I say to my family when they complain of pain. 'don't be so bloody soft'

That can't be pleasant DQ. I will stop moaning.

The pain has changed and isn't constant anymore. It feels like someone is pulling on and heating up one of my veins that runs down the side of my groin. Very unpleasant but a huge improvement over Saturday afternoon.

Listening to my speakers now and I do prefer the speakers along a flat solid wall. Electronics are now between the speakers. Listening to The Comet is Coming CD the bass reproduction has tightened up as has the whole frequency range. Those window recesses which my speakers were in front of are really deep and must sound like echo chambers - that's my subjective view of what has changed. Not such a radical conclusion to come to I guess.

My pain riddled brain must have been playing tricks on me on Saturday when I thought the rear tweeters were causing problems. There is no problem imo but if they are removed I might not hear a difference except the different filter frequency changing as the nominal impedance reduces because of one less tweeter.

I was planning on putting the final build in the outer edges of a bay window at home but I have to rethink that now. Don't want this echo chamber effect again and I presume a bay window will be similar to the two deep window recesses I have in my office.

If I had gone for a simple cube 1 clone with 8" + twitter then this project would have been finished yonks a go. But no and typically for me I am not satisfied and have to make things much harder But the sheer room filling scale and detail of the whole thing assembly takes my breath away and has been more than worth it on reflection.

I wish I had moved my speakers to a flat continuous wall much earlier because I think it has caused me to try and address bass problems that actually weren't the speakers fault at all but where I had them set up. I just thought that was the obvious place to put them as all my speaker set up's have gone there since I was twelve years old (this office / work room used to be my bedroom before I moved out to shack up with my wife).

Going to put on the Portishead Dummy album that has the lowest and most bass of any recording I own. If it copes with that then it will cope with anything. As you can probably see I love the bass to have real impact that you can feel but none of that boomy nonsense that overshadows the rest of the music. It is a tightrope to navigate.

A friend of mine offered to design me a buffer to drive my mighty 833a valve in A2.

Unfortunately, work and health pressures for several months have not given him the time, but today he has sent me the finalised circuit.

I have got 75% of the parts already, so I'll order the remaining parts from HFC (hi-fi collective) then I can sit down and plan the circuit board. This will be made from plain FR4 glass fibre board and turret tags.

The buffer will be driven by a 12A triode and a Hammond 126c interstage transformer.

I like to recycle things. Capitalism and consumerism will be the death of this planet.

So how can I minimise my impact on the environment ? I have bought far too much "stuff" over the years and I never sell or throw owt away. This hoarding disease is facilitated by having a large farm to store things, being a farmer and from Yorkshire Seems I am doomed to a life of clutter.

It does have it's positives however. Access to loads of tools, materials and the space to make a mess and not have to clear it up.

I have a few Naim shoebox enclosures that I should put to good use. NAC72, 2x NAP140, 2x Hicap. The guts of these were long since modified and bodged beyond recognition. So the plan is to house my CD3.5 psu's , TT psu and Phono 3 clone with psu in a separate box.

My only concern is will I get lightning bolts from Doc if I put NVA in a Naim shoebox?

karatestu wrote: ↑Sun Dec 06, 2020 11:17 am I have bought far too much "stuff" over the years and I never sell or throw owt away. This hoarding disease is facilitated by having a large farm to store things, being a farmer and from Yorkshire Seems I am doomed to a life of clutter.

That could be me speaking, Stu. Except for the farmer bit.

Doc would have you hung, drawn and quartered for even thinking about Naim cases.
I say - go for it (pics please).

Fretless wrote: ↑Sun Dec 06, 2020 11:49 am

karatestu wrote: ↑Sun Dec 06, 2020 11:17 am I have bought far too much "stuff" over the years and I never sell or throw owt away. This hoarding disease is facilitated by having a large farm to store things, being a farmer and from Yorkshire Seems I am doomed to a life of clutter.

That could be me speaking, Stu. Except for the farmer bit.

Doc would have you hung, drawn and quartered for even thinking about Naim cases.
I say - go for it (pics please).

Would it be more acceptable if I removed all the olive fascia's and put some black acrylic on instead ?

The agricultural regulator (as Les at Avondale used to say) from a hicap is very similar to the regs in an NVA phono. They use the round can LM317 though and tantalum capacitors. It would be an easy mod to put a LM337 in one side of them for split rail and change the caps.

Or,if the psu is suitable we can connect two LM317 circuits together like you would two AAA batteries also creating pos and neg. The LM317 is said to be a better reg than it's 337 negative counterpart.

Changed my mind about the Naim cases My hifi "sideboard" is going to have every single psu on the ground floor as it were. One big fat mains cable from the NVA BMU to the sideboard where inside it will be split to the various psu's on the lowest level. To fit in an alcove the sideboard will be 95cm wide, 80cm high and 50cm deep.

From the psu's there will be several dc power leads taking the shortest route they can internally to where they need to go. The next level will be 60cm higher than the psu's and will have all six NVA amp boards on it as well as the final smoothing caps, the NVA Phono amp head unit, three input source selector and volume control(s). The selector switch and volume controls will be central to the six amp boards and have very short silver signal wires to each amp board. Phono amp board and regulators will go in a very small metal box before the selector switch at the back of that level.

On top will be my much modified Naim CD3.5 head unit (no psu's) and turntable. TT psu will be on the bottom level. As I want the front of this cabinet to be removable for maintenance I can't put any control switches on the front panel. The selector switch and volume control won't be on the front panel as they will be central to all the amp boards to keep signal wiring as short as possible.

That means they will need wooden dowel extension shafts to the control knows. I can't put the controls on the front panel and I don't want to put them on the top panel. The answer (which I also think will look good ) is to make a bevel where the front meets the top and angle it at 45 degrees. The on/off switch(es) and source selector knob and volume control knob(s) will go there. The source selector switch and volume control will have to be positioned just right and angled so the extension rods go the the bevelled panel on the top corner.

That's it. All in baltic birch ply. Get the chainsaw out. A couple of hours and I should have something knocked up

Good god Stu, that's an immense undertaking, I imagine the lights in your area will dip when eventually switch that huge rug on.