What Are You Building Today

[luvdunhill]

Will do in a bit - no components, but pretty cheap. Info here:

http://www.diyaudio.com/forums/showthread.php?t=313775

[Pars]

Thanks Marc. Yes, I'll take one.

Me: Salas Folded Simplistic Phono stage. I did my own board layout (in Diptrace), based on the diyaudio board, but made a few changes. I built these with parts I had laying around (other than the 2SK369BL quad from Tea Baf on diya and 2SK117GR JFETs which MA Santos was very kind to send to me, as the ones I had weren't high enough in IDSS). Resistors are a combination of Holco 0.1%, PRP, and for values I didn't have, Welwyn RC55 0.1%. I'll probably replace some of the PRPs with Welwyns as well. The caps I had around (MKP1837 and BC MMKP 383), but will probably replace these with some Mundorf Supremes. Target case is a Modushop Slim Line 1U (team single chassis).

Both boards worked fine on initial power up. I am currently leaning towards powering these with either 1 or 2 GRLV plus boards set at 35V (have one built and tested).

If anyone has a good reason to instead use the Salas shunt regs (which I have on the boards, just not populated), let me know what you think. I know a lot of people ooh and ahh over shunt regs, but I'm not quite so sure they are automatically better than a good linear regulator such as the GRLV. Salas' do have a good reputation however.

[recstar24]

9 minutes ago, Pars said:

Thanks Marc. Yes, I'll take one.

Me: Salas Folded Simplistic Phono stage. I did my own board layout (in Diptrace), based on the diyaudio board, but made a few changes. I built these with parts I had laying around (other than the 2SK369BL quad from Tea Baf on diya and 2SK117GR JFETs which MA Santos was very kind to send to me, as the ones I had weren't high enough in IDSS). Resistors are a combination of Holco 0.1%, PRP, and for values I didn't have, Welwyn RC55 0.1%. I'll probably replace some of the PRPs with Welwyns as well. The caps I had around (MKP1837 and BC MMKP 383), but will probably replace these with some Mundorf Supremes. Target case is a Modushop Slim Line 1U (team single chassis).

Both boards worked fine on initial power up. I am currently leaning towards powering these with either 1 or 2 GRLV plus boards set at 35V (have one built and tested).

If anyone has a good reason to instead use the Salas shunt regs (which I have on the boards, just not populated), let me know what you think. I know a lot of people ooh and ahh over shunt regs, but I'm not quite so sure they are automatically better than a good linear regulator such as the GRLV. Salas' do have a good reputation however.

Let me know your thoughts on the sound once you’ve had a chance to break it in a bit. Or feel free to bring it over here for a beer and listen to some vinyl at my place

[Pars]

Thanks Ryan! Maybe I'll take you up on that once I have it built (kinda). This is set for somewhat specific loading for an AT ML440, so I would want to match it somewhat to your cart. I'll pm you when I have it more or less done and we can go from there. I haven't had a turntable setup in years. My table isn't exactly up to HC standards either (Thorens TD320).

[recstar24]

21 minutes ago, Pars said:

Thanks Ryan! Maybe I'll take you up on that once I have it built (kinda). This is set for somewhat specific loading for an AT ML440, so I would want to match it somewhat to your cart. I'll pm you when I have it more or less done and we can go from there. I haven't had a turntable setup in years. My table isn't exactly up to HC standards either (Thorens TD320).

You got it. I’m pretty happy with my vinyl rig, the 1200GR with ortofon 2m blue is a nice match. I like my Hagerman but I would say it’s probably the limiting part in my rig and I would be curious what the next level in phono stage has to offer. 

[Pars]

This probably got buried in my post:
No one has an opinion on shunt vs. linear reg for a phono stage? Specifically, Salas shunt vs. GRLV plus?
Thanks for any thoughts!


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[jose]

I have finished my GRLV "portable"

[luvdunhill]

More buffers - 10 transistors per board!

 

[mention=431]Pars[/mention], interested in my two purple prototypes? Rails are 5v-50v and implements a kind of sliding bias (bias increases when load increases) centered around 10mA. They are DC coupled and low distortion. I will run all the new ones through the distortion jig in the morning and see how close they are.

 

[swt61]

Speaker boxes now clad in Black laminate, because we had enough left over from the router table project...

Making a solid Cherry 3/4" thick baffle to glue on top of MDF baffles...

[luvdunhill]

More buffers - 10 transistors per board!
 

Kinda cute finding. The best matched JFETs from my pile, when stuck in the final circuit, result in -92dB THD and -84dB THD+N off my battery powered oscillator. That’s 0.0025% THD. The worst possible match (deliberately bad match) is -82.6dB or 0.0075%. Now, the offset trimmer value can be used to find the better performing circuit, as out of the 8 finished buffers, this trimmer value when DC offset is at zero, is directly proportional to the resulting THD value (this is because these JFETs aren’t really good complementary devices and so it all makes sense, just randomly noticed this when double checking some voltages)

[swt61]

Milo and I got the speaker boxes mostly complete today. Made some round holes and some rectangular panels.

Tweeter holes are in the Cherry baffles only, as they're not deep enough to need holes in the MDF panel too. Woofer holes and port tube holes in back.

Cherry baffles got milled and drilled as well. And the first coat of Arm-R-Seal. The fluting is strictly aesthetics.

[luvdunhill]

Nice!

[Pars]

Very nice Steve (and Milo)!

So you like Arm-R-Seal? I've always used Varithane. Is something like Arm-R-Seal what you would recommend for a natural cherry finish? Thinking about building a Salamander Synergy clone, but need to draw up plans for it.

[swt61]

Arm-R-Seal is a urethane modified Tung oil. You get the beauty of Tung oil and the durability of Varithane. Plus it's a wipe on finish, so easy as pie. 

[guzziguy]

Easy as pie sounds good.  How would it look on white oak?  Other than sanding, is there any other prep needed?

[dsavitsk]

16 hours ago, swt61 said:

and the durability of Varithane

Speakers look great, but I'll never understand the desire of woodworkers to hand make things out of natural materials only to coat them in plastic.

 

[jose]

19 hours ago, swt61 said:

Cherry baffles got milled and drilled as well. And the first coat of Arm-R-Seal. The fluting is strictly aesthetics.

Beautiful... I can not stop looking at it

[Voltron]

And I have a can of Tried & True sitting on the shelf right next to that plastic stuff...

[Voltron]

Milo has another type of woodworking to do. 

[swt61]

8 hours ago, dsavitsk said:

Speakers look great, but I'll never understand the desire of woodworkers to hand make things out of natural materials only to coat them in plastic.

 

Hmmm, I thought straight guys wrapped their "natural materials" in "plastic" all the time.

7 hours ago, jose said:

Beautiful... I can not stop looking at it

Thanks! I was trying to make them look high end. Sonus Faber and Chario were my inspiration.

1 hour ago, Voltron said:

Milo has another type of woodworking to do. 

 

 

 

Good thing Otis doesn't have much going on Saturday. We'll make 'em spiffy!

[Voltron]

[jose]

 

For your next project maybe?

 

 

Edited April 10, 2018 by jose

[swt61]

[swt61]

Milo was nice enough to finish the finish on my baffles.

They look fantastic. Milo really is a handy guy!

[wink]

22 hours ago, jose said:

 

For your next project maybe?

 

 

Hows about this...? the venerable JBL Paragon.....

 

Edited April 11, 2018 by wink