My VTA ST-120 is on the way .....and other loose ramblings of an old fart

I'm pretty sure I've heard or read that many tubophiles are of the belief that adding anything solid state into the path of the signal from the source to the speaker detracts from the sonic pleasures of tube sound ...whether it be the preamp or any type of equalization or crossover. Now I've considered using a mini DSP to bi-amp my setup...but I wasn't going to let anyone here know... :-)

Passive crossover ...tweak by changing physical components (inductors, capacitors, resistors, etc.)

CletusB wrote:Passive crossover ...tweak by changing physical components (inductors, capacitors, resistors, etc.)

Yep. It's work but worth it.

deepee99 wrote:

CletusB wrote:Passive crossover ...tweak by changing physical components (inductors, capacitors, resistors, etc.)

Yep. It's work but worth it.

Hell yeah!!

BTW folks, here's an excellent and inexpensive piece of test instrument kit for the lab.

https://www.amazon.com/Multifunction-transistor-Capacitor-Inductance-screwdriver/dp/B071Y5CHPK/ref=sr_1_3?ie=UTF8&qid=1523188548&sr=8-3&keywords=mosfet+tester

Got up early and tackled rebuilding my Source Selector / Stepped-Attenuator Box "Zero-Preamp" this morning to allow for more stereo source inputs

Switch Positions:  
1   BLANK (clamps to ground, used as a "mute")
2   CD Transport (my trusty Pioneer PD-4500)
3   Rpi DAC / Server
4   Feed from the Studio Mixing Console
5   AUX 1 (available)
6   AUX 2 (input jacks located on front panel, used for quick input access, eg. hooking-up the signal generator or Smartphone)

Here's a shot of one of my "temporary" Passive Crossovers, it's been "temporary" for nearly 20-years now and has been tweaked and tweaked over the years!  ......but it just sounds so damned good!
One day it may get rebuilt with some really high quality components (yeah right!)

Swapping those iron core chokes with air core and electrolytic caps with film would make that sound better.  Although they may not fit in that box.

corndog71 wrote:Swapping those iron core chokes with air core and electrolytic caps with film would make that sound better.  Although they may not fit in. that box.

Oh yeah, I'm with you on that for sure, and that's been the plan. But it gets kinda pricey to do it right. Will get around to it later this year, when I can free-up some budget again.

Dogstar wrote:I'm pretty sure I've heard or read that many tubophiles are of the belief that adding anything solid state into the path of the signal from the source to the speaker detracts from the sonic pleasures of tube sound ...whether it be the preamp or any type of equalization or crossover. Now I've considered using a mini DSP to bi-amp my setup...but I wasn't going to let anyone here know... :-)

I guess I'm safe then - I went with a software approach here, adjusting the digital output of my HTPC before it even gets out of the computer.

Tried the MiniDSP, but it was a PITA to program. It would also lose the programming every now and then. Grrrrr ... Then went with using the "convolution kernel" built into jRiver Media Center and the same curve I'd been using for the MiniDSP - Room EQ Wizard can export that directly to jRiver. Excellent results, easily as good as the MiniDSP,  and as easy as pointing the software to the curve file on the hard drive. Set it all up a couple years back with no further tweaks required.

PS - I've ripped my collection (vinyl and all) to digital, but I can use the original source if I'm feeling ambitious, using a parametric EQ. Granted, nowhere near as accurate as what I get from the software solution, but I was able to target the big lumps using the REW printout for satisfactory playback. I just got to remember to turn the PEQ on when needed - and turn it off when not. That can get interesting as most of my problems are at the bottom end, and I end up with double or nothing with a chance of serious boom if I'm not careful.

My subwoofers and their associated amplifiers are solid state, as is the branch of an electronic crossover to feed them. The path to the main speakers is all-tube.

The CD, cassette and tuner sources are transistor; the CD and cassette just about have to be,
and FM reception from stations I would listen to is too weak here for any tube tuner I've tried,
though a Sherwood S-3000 II was good in mono, and I have not tried a Marantz 10B.

Decided to order a set of Dayton Polyprops to replace the electrolytics in the x-overs ....actually we're trying to fix something that ain't broke!  cause it sounds damned good as is!

Will start there, the iron core chokes are operating well below saturation at my audition levels and I very much like the way the system sounds now anyways. But I can certainly justify changing out those old electrolytics now. Even playing for extended periods and loud levels for a recent family gathering here, the old iron-cores held their own very well

Time to make the music system "Smart"!
February last year (while recovering from spine surgery  ....I just can't stay still for long), I made the entire house and workshop "Smart", using Samsung's SmartThings and Alexa.  Ever since, we voice and smartphone control the entire house. There's also time based and geofenced automated house configurations for when we've left or returning to the house, along with motion-sensed lighting for certain rooms, and other pre-programmed automated response routines for lighting, security and energy management.
We have not touched a wall-switch in over a year, seriously!   ....mostly just shout-outs to Alexa when we want something on or off or the TV channel changed!   
Yesterday, I realized that I went off on a service call and forgot the music-system including the ST-120 on (not good!).
So, the new project on the white-board, is to get the music-system on the home automation network. I am building a Z-wave relay box that will accomplish this and also give me a nice Volts, Current, Power display, along with a latch-out should power fail (manual reset mandatory).
Will post some pics here in the upcoming days, although it's really simple.
Here are some key components:
https://www.amazon.com/gp/product/B000XU5MEG/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0035YRCR2/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B004YW5CWQ/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1    ---  Not needed - The Smart-Switch has relay switching good to 15A

https://www.amazon.com/gp/product/B06XRW1ZHK/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

https://www.mouser.com/ProductDetail/TE-Connectivity-Corcom/10VS1?qs=TukW%2FaGuJ4Oeuy%252bp7I%252bJDg%3D%3D

...and found these enclosures locally very inexpensive (US$13.00)
https://articulo.mercadolibre.com.ar/MLA-700581013-caja-de-pase-estanca-ip65-roker-pvc-pr100650-165x165x50mm-_JM

....built similar relay boxes for AC control here, so I know they work a peach, but the one for the music-center will be a little more "elegant"

Now there's been quite a bit of run-time on the system, here's the max logged pwr transformer temp:

Cool !

No more rushing out and forgetting the music system on.  My Smart-Switch, Power Monitor and RFI Filter.
SmartThings / Alexa has control, I can power On/Off via Local SW, Voice Command, SmartPhone and also powers-down by Geofencing when I am more than 2km away (smart-phone GPS).

Bunch of audio caps and XT-60 connectors just came in for upgrading my Linkwitz-Riley Passive Crossover Networks. Making the caps plug-in so I can tweak and roll components.

Done, and I can detect no sonic difference to the old electrolytics. Glad I did it nonetheless, they'll last and I won't have to worry about them.  Will sweep the frequencies tomorrow and see what the spec analyzer has to say compared to the last sweep  .........yes, I know it's a mess!

Do you have a schematic of the crossover? Those caps may not make as much of a difference if they’re not in the direct signal path. Plus I’ve used those Dayton caps and while they get the job done, there are more transparent caps out there. Consider Sonicaps in the signal path for a little more air and detail.

Well, they're just typical garden variety, Linkwitz-Riley networks, no specific schematic handy.
A little (marginally) tighter bass response maybe? ...but that's soooo purely subjective, and could be just my mood now or the color of the shirt I'm wearing.
I love the sound of my system. Thanks, I'm good for now and not going to go chasing something these old 63-year ears can't respond to.

CletusB wrote:BTW folks, here's an excellent and inexpensive piece of test instrument kit for the lab.

And here I thought capacitor ESR testers were spendy. Hmmm....

CletusB wrote:
Done, and I can detect no sonic difference to the old electrolytics. Glad I did it nonetheless, they'll last and I won't have to worry about them.  Will sweep the frequencies tomorrow and see what the spec analyzer has to say compared to the last sweep  .........yes, I know it's a mess!

What are you using this for? Is it a 3 way or what?

jfine wrote:

CletusB wrote:
Done, and I can detect no sonic difference to the old electrolytics. Glad I did it nonetheless, they'll last and I won't have to worry about them.  Will sweep the frequencies tomorrow and see what the spec analyzer has to say compared to the last sweep  .........yes, I know it's a mess!

What are you using this for? Is it a 3 way or what?

Three way crossovers for my VOTTs,  550Hz and 6KHz
Cheap units made by Audio Pipe. Typical Linkwitz-Riley networks on a decent PCB, which I've had for like 20-years (think they were originally in my lab at the Samsung factory back then, when we played with some home stereo speaker designs) and they've worked well all along, I've tweaked them quite a bit over the years adding L-pads and such. Just thought the caps could do with a change-out about now.
The original electrolytics actually still measure decent

jfine wrote:

CletusB wrote:BTW folks, here's an excellent and inexpensive piece of test instrument kit for the lab.

And here I thought capacitor ESR testers were spendy. Hmmm....

Nope!  Multifunction Meter  Can't beat it for $15 and it quickly tests and identifies all sorts of components (bipolars, fets, mosfets, diodes, chokes, caps/esr, resistors)   ....I really use it a lot.

CletusB wrote:
Three way crossovers for my VOTTs,  550Hz and 6KHz
Cheap units made by Audio Pipe. Typical Linkwitz-Riley networks on a decent PCB, which I've had for like 20-years (think they were originally in my lab at the Samsung factory back then, when we played with some home stereo speaker designs) and they've worked well all along, I've tweaked them quite a bit over the years adding L-pads and such. Just thought the caps could do with a change-out about now.
The original electrolytics actually still measure decent

My guess is the those larger value electrolytics are likely on the low frequency circuit, maybe zobel like, probably wouldn't hear much diff changing those, tighter would be about it. The yellow mylars OTOH likely are mids and/or highs, probably would affect sonics much more if changed out (mylar in xover always bothered me JBL uses them a lot, I can't unhear them now), but Dayton for those? Not worth it. Mundorf silver/gold/oil or beeswax jupiters, much better. But if it sounds good then why mess with it, and hey what do I know.