Salt Cellar Initiative

[mwhouston 4,443]

To get a grasp of where I’m am going with this thread you need to of read or have read  this article. 
 

https://www.stereophile.com/content/gramophone-dreams-34-salt-cellar-system

 

If you go no further at the least it is in interesting read. Some will go “meh” others will take it on board to search for better reproduction. Maybe even build there own SC. The challenge I have given myself and would like to throwout to others is can you build or hobble together a “Salt Cellar“ (SC) system. The core of a SC system is purity of sound, dynamics and immediacy. 
 

These are the constrains/opportunities I’m am pursuing;

 

• a monaural system
• high efficiency speakers - horns where possible
• a tube low power Class A mono power amp or even tube integrated amp
• vintage tubes
• mono vinyl phono playback from mono cart or mono wired phono stage 
• ultra short non shielded interconnects and speaker leads of Silver plated wire wrap wire

?

Ive been tossing this temp system around since I read that article and now have  (in my head) a whole SC system. So cutting to the chase I’m going to build a mono integrated wine box tube amp based on some vintage 807 and RCA 6SN7. Half the 6SN7 will be a single stage preamp and the other half the driver for a Suncalc designed 807 amp.

 

Speakers will be my Beyma 12” concentrics with a Altec 511B horn and FatalPro driver. The horns will handle mid-range and the tweeter in the horns super tweeters. Overall efficiency about 98db. 
 

Im current working three other projects but now taken on a forth for a true SC system. Any other takers out there. 

[sir sanders zingmore 11,283]

I shall follow this with interest!

[mwhouston 4,443]

9 minutes ago, sir sanders zingmore said:

I shall follow this with interest!

10% for the first twelve months, after tax. 

[mwhouston 4,443]

Here is the schematic for a stereo 807. I’m building the mono version with some well used Vintage tubes.  Also here is my build of the 807 designed by Suncalc on diyaudioprojects site. 
 

https://retro-thermionic.blogspot.com/2012/03/luciano-807-power-amp.html

 

[Mullet 37]

Very interesting.

[mwhouston 4,443]

I download the Fed McDowell music. Really couldnt see (or hear) any value in it. I have far better all analogue tracks which will pepper up the SC system. 

Edited June 14 by mwhouston

[davewantsmoore 6,259]

I like this.

 

1 hour ago, mwhouston said:

These are the constrains/opportunities I’m am pursuing .....

 

Quote

Griesinger's main requirements for improved clarity are: a) maintain a high ratio of direct to reflected sound, and b) preserve the phase (time) coherence of harmonics of (voice range) sound.

That is what you need to do to get the magic.

 

Source, doesn't matter....Electronics, doesn't matter.... as long as each are relatively well engineered.

 

Horn and open baffle (dipole) speakers both have a higher direct to reflected ratio than monopoles.    They are what you need for a) ... but it has to be very well designed to get b) too.    There are a lot of horn and dipole examples out there which have serious problems... and don't "do it".

 

Quote

can you build or hobble together a “Salt Cellar“ (SC) system

For home hifi SPL levels.......  Build a single big horn, and drive it with a ~2" cone driver .... crossover at about 300Hz to a large woofer.

 

1 hour ago, mwhouston said:

Altec 511B horn

I worry that the XO from this to the 12" will fall within the voice range.... and so you do not get b)

 

 

I have both a "PSE144" horn, and a 4 way dipole speaker (like a Linwitz LX521 / Nao Note) .... and they both do it .... although the PSE a little better.

It is the higher direct to reflected ratio which is the biggest part.    It is a huge jump in "clarity".

 

 

[mwhouston 4,443]

I doNt expect the 12” Beymas/horn combo to be the best it’s more about, as in the article, hobbling together a different base system and see what eventuates.
 

I chose the 807 because of its top cap and I wanted that Ye olde look. Not only that they are the choice of some serious tube lovers. Will on.y be a few watts but with 98db efficiency in the speakers there should be good volume. Not expect big bass but should be sufficient. The Beymas get down to 50hz with my other tube amps. 

 

 

[mwhouston 4,443]

I have Grade mono cartridge but I thought of this method to convert my stereo carts to mono. MM is to see 44K.

[davewantsmoore 6,259]

2 hours ago, mwhouston said:

I doNt expect the 12” Beymas/horn combo to be the best it’s more about, as in the article, hobbling together a different base system and see what eventuates.
 

I chose the 807 because of its top cap and I wanted that Ye olde look. Not only that they are the choice of some serious tube lovers. Will on.y be a few watts but with 98db efficiency in the speakers there should be good volume. Not expect big bass but should be sufficient. The Beymas get down to 50hz with my other tube amps. 

I think efficiency is only relevant when "you don't have enough".     What is "enough" is complicated.... but I think people chase it thinking it is responsible "for the magic", when it really isn't.

 

Directivity in the voice region is what they're talking about ..... keeping it suitably "narrow" (keeping in mind that almost all speakers are "very wide" in this region) ..... and keeping the phase correct (at all listening angles).

 

You will need to avoid "wide" in the 300 to 1200Hz region .... and avoid a change in directivity (or at least a sharp one).

[mwhouston 4,443]

I have all the parts I need to make the 807 triode Salt Cellar mono amp.  I think part of this project is to hobble together an amp cheaply and with parts on hand.  I have only had to shell out about $12 for some tube sockets Top cap for the 807. Everything else I had in de lab.

 

To keep cost down I’m making another wine box amp and are yet to drill and stain the box.  The big “Tranni” looking device is a Hammond  choke 10H 125mA. Tubes are all RCA 80 (rectifier), 6SN7 and 807.  An external universal Tranni box will supply 12VAC AND 250VAC. I think tube rectification is a must. The 80 is quite an old tube from the 1940s. 

[Lansche plasma guy 243]

Ideally with this sort of system speaker you really want a large and wide dispersion horn.  I did something similar many many years ago with a large multi cell altec horn and a altec a5 box.  Transformers and blended stereo to mono.  

 

Cant wait to read your progress.

 

LPG

[mwhouston 4,443]

13 minutes ago, Lansche plasma guy said:

Ideally with this sort of system speaker you really want a large and wide dispersion horn.  I did something similar many many years ago with a large multi cell altec horn and a altec a5 box.  Transformers and blended stereo to mono.  

 

Cant wait to read your progress.

 

LPG

It’s about what’s on hand. Luckily I have the Altec 511Bs and bass via the 12” Beymas. 

[mwhouston 4,443]

Before amassing parts for the dedicated SC integrated amp I thought I could just use one channel of one of the two 6L6 SE UL amps I already have. The speakers aren’t an Issue as I have two pairs of Altec 511Bs With FaitalPro compression drivers. One pair just doing nothing and the Beymas are in system two. Easy to put together and Xovers are already setup. 
 

I have a RCA setup which blends the two channels to one which I use for testing amp. After I have drilled and stained the new amp wine box I may just set this up for a listen. The 6L6 certainly looks the part though not triode. But it could be made triode. 

 

https://retro-thermionic.blogspot.com/2017/07/retro-6l6-se-ul-mkii-power-amp.html

 

 

 

 

 

 

 

[acg 2,541]

@mwhouston, I'm also interested to see where you end up with this effort.  I know someone that has heard the Slagle/Jackson ETF Salt Cellar system and apparently it was/is something special.  Big mono, horns, DHT amps, an old Garrard (if I remember correctly) TT with a bespoke cart and LR phono.  A wonderful use of old tech with new methods and components, some a century old, but still able to wow us.  Even disregarding the value of the drivers and horns, there is a tremendous amount of $$ invested in that 'simple' mono system, more than most of us have invested in our own systems.  Not that $$ = SQ of course.  I suggest that the reported SQ of the system is as much a result of the knowledge of the two guys that put it together as the precise components used, although they did build most of the components themselves.

 

I see you are not building a DHT amp using the ancient 50 mesh plates though...hehehe...I can't afford them either.

 

 

[mwhouston 4,443]

3 minutes ago, acg said:

@mwhouston, I'm also interested to see where you end up with this effort.  I know someone that has heard the Slagle/Jackson ETF Salt Cellar system and apparently it was/is something special.  Big mono, horns, DHT amps, an old Garrard (if I remember correctly) TT with a bespoke cart and LR phono.  A wonderful use of old tech with new methods and components, some a century old, but still able to wow us.  Even disregarding the value of the drivers and horns, there is a tremendous amount of $$ invested in that 'simple' mono system, more than most of us have invested in our own systems.  Not that $$ = SQ of course.  I suggest that the reported SQ of the system is as much a result of the knowledge of the two guys that put it together as the precise components used, although they did build most of the components themselves.

 

I see you are not building a DHT amp using the ancient 50 mesh plates though...hehehe...I can't afford them either.

 

 

The only thing I have built DHT is a preamp with century old tube.  Astonishingly good.  Drilled the wine box today hope to sand and stain tomorrow. 
 

http://retro-thermionic.blogspot.com/2020/04/mwh-1920s-ux-171a-tube-preamp.html

 

[acg 2,541]

Yes, saw that one when I had a look at your site earlier today.

 

I have a DHT midrange channel.  Can use 2.5V or 4V tubes such as 45, 2A3, RE604, YO186.  AC heating and dead silent with your head in the 112dB/w/m midrange horn.  Uses a Dave Slagle 80% mumetal output transformers.

 

Will soon build my own DHT preamp for kicks...71a, 45, YO186 and 801a will be tried.  VC will be Slagle autoformers.  If the pre ends up with output transformers no doubt they will be Slagle mumetal.  The integrated LCR phonostage has Slagle mumetal inductors and MC SUT's.  Could say I like his work... 

[mwhouston 4,443]

3 hours ago, acg said:

Yes, saw that one when I had a look at your site earlier today.

 

I have a DHT midrange channel.  Can use 2.5V or 4V tubes such as 45, 2A3, RE604, YO186.  AC heating and dead silent with your head in the 112dB/w/m midrange horn.  Uses a Dave Slagle 80% mumetal output transformers.

 

Will soon build my own DHT preamp for kicks...71a, 45, YO186 and 801a will be tried.  VC will be Slagle autoformers.  If the pre ends up with output transformers no doubt they will be Slagle mumetal.  The integrated LCR phonostage has Slagle mumetal inductors and MC SUT's.  Could say I like his work... 

where are the OPTs used. Got an image got a link? Could say? Would say!
 

Did you see my 1/3W 1920s 71A power amp in a 1940s pot stand.  Nickel core Hammond interstate trannies as input/drivers. 
 

https://retro-thermionic.blogspot.com/2013/03/intermezzo-1920-ux-171-power-amp.html

 

[acg 2,541]

Yes, I remember your 71a power amp.  Nice job!

 

 

Here are the Slagle OPT's.  They do not need to pass the full frequency range because a line level passive filter is included at the input to the amplifier thus restricting the amplifier output and enabling a direct connection from OPT to compression driver (no speaker level filter).  It works a charm.

 

 

 

Here is a photo of the midrange Slagle OPT against other OPT's used in the amplifier.  That Black Art bass output transformer is a beast made on 6" lams...look at it's specs...it takes full power from a 6c33c and directly drives a 1R speaker (subwoofer) load down to 6Hz.

 

 

 

A shot during construction...in the foreground you can see the bottom of the midrange horn the Slagle OPT in the background drives...

 

 

 

My system currently is a lot like your Salt Cellar system in that I use horns and triodes and due to a ridiculous workload have only (mostly) finished one side and am listening in mono.  Sounds freakin awesome though.

 

 

 

 

Edited June 22 by acg

[mwhouston 4,443]

47 minutes ago, acg said:

Yes, I remember your 71a power amp.  Nice job!

 

 

Here are the Slagle OPT's.  They do not need to pass the full frequency range because a line level passive filter is included at the input to the amplifier thus restricting the amplifier output and enabling a direct connection from OPT to compression driver (no speaker level filter).  It works a charm.

 

 

 

Here is a photo of the midrange Slagle OPT against other OPT's used in the amplifier.  That Black Art bass output transformer is a beast made on 6" lams...look at it's specs...it takes full power from a 6c33c and directly drives a 1R speaker (subwoofer) load down to 6Hz.

 

 

 

A shot during construction...in the foreground you can see the bottom of the midrange horn the Slagle OPT in the background drives...

 

 

 

My system currently is a lot like your Salt Cellar system in that I use horns and triodes and due to a ridiculous workload have only (mostly) finished one side and am listening in mono.  Sounds freakin awesome though.

 

 

 

 

Great work. What Is the tube compliment. 

[mwhouston 4,443]

In my 71A preamp and power amp the tubes have nickel plates. Also the input Tranni for the power amp has a nickel core. I’m wondering just how much nickel adds to the sound? Both are extremely engaging to listen to. 

[acg 2,541]

All Russian right now, and all wired in triode:

• Sub and Bass and Upperbass channels all 6e5p driving 6c33c-b (either one or both filaments)
• Fundamentals Channel 6e5p single stage triode
• Midrange 6e6p driving DHT (currently using YO186, have some 45's here to also try at some stage)
• HF 6e6p single stage

[acg 2,541]

3 minutes ago, mwhouston said:

In my 71A preamp and power amp the tubes have nickel plates. Also the input Tranni for the power amp has a nickel core. I’m wondering just how much nickel adds to the sound? Both are extremely engaging to listen to. 

 

If you listen to some, the more nickel in the transformer the better the sound and I tend to agree within limits.  There are varying amounts in use though, 40% nickel is relatively common but 80% nickel starts to get expensive and is easier to saturate.  It is also horses for courses.  I've used 80% nickel in the crucial midrange channel, amorphous Lundahl in the lower channels and some good steel lams for the subs where inductance rules because that seemed the best use cases for each.

 

In the phonostage and preamp it will be all Slagle 80% nickel right from the SUT's to inductors to output transformers and autoformers.  All that iron is sitting here on my desk as a reminder to get to the build. 

[mwhouston 4,443]

There are a number of pentodes and tetrodes etc. I could have used as the power tube. In all  cases I would.d have triode strapped them. I do know some tubes “triode” better than others.

 

Just a few tubes I have on hand (and not just pentode) and could of used are; KT88, EL34, 6V6, 6L6, 6EM7 (is a dual triode), 6T9 (triode and pentode) and a little metal fellow - the 12A6 (see link) - 

 

https://frank.pocnet.net/sheets/049/1/12A6.pdf

 

But staying with the Salt Cellar Initiative it must have a top cap. In de lab this was my only tube I knew I had both a cct. for and had a top cap. 
 

I have seen a schematic or two using a 12A6. Could be the next SC amp.    

 

 

Edited June 23 by mwhouston

[mwhouston 4,443]

A Salt Cellar/Steam Punk combo may be interesting. No I’m just making a plain SC amp. I may also make a SC mono MM tube phono stage. 
 

Edited June 24 by mwhouston