Request for Advice on Upgrading Spendor Crossovers

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atkinsonrr

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Hello -- 
I enjoy a pair of Spendor S-100 speakers driven by all tubes: Mac MC275; Mac C2200 Pre-amp; Line Magnetic tube DAC.  The drivers are a 0.75" soft dome tweeter crossing @ 4Khz to a 6" polypropolene mid which crosses over to a doped bextrene woofer at 600Hz.  As you might be able to see in the pic below: 

--The stock crossover has 4 inductors--but do not know values as none are marked.
--At middle of the left side of the board in the pic, the High Freq section currently has one Vishay MKT1822 1.5uf 100VDC cap; one Vishay MKT 1822 .33uf 100VDC cap and one Vishay MKT1822 6.8uf 100VDC cap. 
--At the top left corner, the Mid Range section has one Vishay MKT1822 1.5uf 100VDC cap and one Vishay MKT1822 4.7uf 63VDC cap.
--Across the right of the pic from bottom to top, the Low Range section has three unknown brand .6R MKT caps marked "10J60" right at the take off to the woofer, then two Bennic Bi-Polar 20mfd 50W electro caps, then one unknown brand 6.8 MKT cap marked "J100" then another unknown brand .6R MKT cap marked "10J60".   
--All caps are bypassed with Vishay MKP 1837 .01 under the board.

Objectives: to improve the definition, detail, openess, spaciousness and imaging without damaging the listenability, body and smoothness this speaker is noted for. I have always been very sensitve to glare in a system, so need to avoid it at all costs. I think one might describe the kind of sound I seek as being close to a vintage tube sound, picking up the sweetness, body, tone and texture but avoiding the closed-in, lack of detail, lack of dynamics that "vintage" might connote to some.  I would like to find the most-leveraging improved passive components to achieve this.  And I would like to have them fit on the current crossover board.  Would also like to achieve this with an eye toward diminishing returns. I don't have an interest in cost-no-object solutions, as I have found in the past that (for me) they are usually not worth it.

Mission impossible?   :icon_lol:

Based on my research, as a way to start the conversation, and give y'all something to react to here is what I am thinking might be one solution:
1. All Sonicap Gen 1 Caps, use Russian PIO's (that I have on hand) as needed to tailor the sound.  Cost would probably be under $80 for both speakers.
2. Bypass Sonicaps with the existing MKP 1837 .01's as suggested in the Humble Homemade HiFi Cap Survey (or has he moved on to the Cornell Dubilier 940C for all bypass applications?--in which case I may try those if y'all think worthwhile).
3. Use Mundorf M-Resist (replacing their steel legs with copper wire) to replace the two resistors.
4. Not sure if anything need be done with the inductors or even how to know what value the current ones are.

I welcome all feedback.  Thanks so much! 





PMAT

Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #1 on: 1 Feb 2018, 06:27 am »
Are those all solid core inductors?

atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #2 on: 1 Feb 2018, 07:11 am »
Hi PMAT--

Love your avatar.  Hope things are getting back to normal in Santa Rosa.  Used to live in the Bay Area, still miss it sometimes. 

Yes, I think they're all solid core.  I was really surprised to find 4 inductors.  I mean, I've only got three drivers!  This means one of the drivers is run through 2 inductors? 

Jeff

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #3 on: 1 Feb 2018, 07:20 am »
I enjoy a pair of Spendor S-100 speakers driven by all tubes: Mac MC275; Mac C2200 Pre-amp; Line Magnetic tube DAC.  The drivers are a 0.75" soft dome tweeter crossing @ 4Khz to a 6" polypropolene mid which crosses over to a doped bextrene woofer at 600Hz.

Hello, welcome to my circle.  I would love to hear how you arrived at this system over the past 10 years, looking back at your older system.

Quote
As you might be able to see in the pic below:

After years in the industry, this has become a pet peeve for me.  I do not want this to (nor do I believe it will) discourage others from speculating on your proposed project.  While a pic is necessary to consider what (brand/type component) is there when plotting the map to your desired result, it is not a substitute for a schematic.  I have a few Spendor schematics, but no S100.  The closest thing i have is a SP100.  Looking back at your previous posts, a simple schematic should be nothing for you :wink:

Quote
All caps are bypassed with Vishay MKP 1837 .01 under the board.

Was this factory, or did you do it?  If you did it, what was the result?

Quote
improve the definition, detail, openess, spaciousness and imaging without damaging the listenability, body and smoothness....picking up the sweetness, body, tone and texture but avoiding the closed-in, lack of detail, lack of dynamics...

Would you like the next winning powerball #s with that :o :lol:

Quote
Would also like to achieve this with an eye toward diminishing returns

Quote
I would like to have them fit on the current crossover board

Quote
All Sonicap Gen 1 Caps, use Russian PIO's (that I have on hand) as needed to tailor the sound.  Cost would probably be under $80 for both speakers

Quote
I would like to find the most-leveraging improved passive components to achieve this

 :scratch:  There are a few conflicts here.

Quote
Mission impossible?

Perhaps.

Given your multiple references to budget, do not keep us in the dark.  What is you proposed budget?

Quote
Based on my research, as a way to start the conversation, and give y'all something to react to here is what I am thinking might be one solution:
1. All Sonicap Gen 1 Caps, use Russian PIO's (that I have on hand) as needed to tailor the sound.  Cost would probably be under $80 for both speakers.
2. Bypass Sonicaps with the existing MKP 1837 .01's as suggested in the Humble Homemade HiFi Cap Survey (or has he moved on to the Cornell Dubilier 940C for all bypass applications?--in which case I may try those if y'all think worthwhile).
3. Use Mundorf M-Resist (replacing their steel legs with copper wire) to replace the two resistors.
4. Not sure if anything need be done with the inductors or even how to know what value the current ones are.

How did you come to this?  Which Russian PIOs?  Are you referring to Mundorf Supreme resistors, or...?

We can measure those inductors for you free of charge.  We would even draw the schematic if you sent the board :D

atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #4 on: 1 Feb 2018, 08:30 am »
Hi Jeff--

Thanks for your interest.  Here are the answers to your questions.

How did I evolve to this system?  Since my first real job out of college (late '70's) thru much of my audio life I was in love with planars and electrostats.  They project a presence that cannot be denied. Believed in high tech, built a couple of Class D amps.  Didnt really trust tubes. Always solid state power amps but a couple tube preamps by Audio Research and CJ. By the early 2000's I felt I was always chasing satisfying sound but never getting there.  Went through a complete reappraisal.  And put together one of the more satisfying systems with Vandersteen 5As and tube monoblocks.  Realized I found the old dynamic box speakers to be more satisfying and musical.  Esp. British voiced speakers and Vandy's. And as I moved to McIntosh the tube reliability was there.  Not the latest and greatest whiz bang but unlike the SS and electrostats never amusical, annoying or leading to a fixation on the damn equipment.

Schematic  OK will have to pull the board (not fun) to trace the traces, but can do. 

Did I update and bypass the caps?   Yep. The MKT1822s on tweeter and midrange I changed out and then did the bypass caps as well.  It was an improvement.  Nothing earth shaking.  I would say less grain, a bit more detail, a bit less closed in. 

Conflicts?  I'd rather say some of my stated needs engage in healthy competition. But thats how we'll get to a robust and balanced solution.  Besides seems like the most efficient way for all the fine folks here to understand where I wanna go with this.  C'mon buck up!  We can do this!  :lol:

Budget  I would say less than $500 unless someone is really persuasive re: the next big leap is just another hundred away...  I have seen too many posts where folks are spending thousands on xover caps alone.  That used to be me, but I'm older and wiser now.  Aint I?   :?

How did I arrive at my Strawdog   Obsessive review of posts just like this one, going back to 2005.  And put through my particular screens: looking for where the diminishing return curve flattens; avoiding anything called etched or detailed or fatiguing; trying to triangulate from many opinions something that conforms to how I hear; knowing that striving for the nth degree of detail or transparency often works at odds to musical and satisfying (as my journey with electrostats and solid state taught me well); not needing the BEST! as there is no best, only what works with my ears and my system.

Measure the Inductors?   Hey you didnt even tell me I needed inductors yet!  Can I measure them?  No advanced weapons here, but do have a good Fluke VOM and an ammeter.  Hate to be without the big spendors.  TX is so far away!

Hope this helps -- Rob

 



atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #5 on: 1 Feb 2018, 08:55 am »
Oops sorry.  Missed a couple of your questions at the end there.

Which Russian PIO's  Got some K40Y9's in .1uf and 0.01uf; some K75-10's in 0.47uf.  Also some American Vitamin Q's in 1uf, 0.1uf and 0.01uf.  Also a few old American Good All caps in 0.047uf.  Also a couple of Chinese Sequa's in 0.01uf.  Also four batches of Russian MBM's (which are paper in wax) in 1uf, 0.5uf, 0.25uf, and 0.1uf.  Actually, think I bought the MBM's from you just a week or so ago. Have not tried them yet.  Never met an oil cap I didnt love.  Just a few days ago bypassed the boutique output film caps that came in my DAC with a couple of K40Y9's and WOW!  Didnt know the the old Spendors could throw space like that!

Supremes?  Yes, sorry the full name is M-Resist Supreme Wirewound 20 Watt Non-Inductive.

 

LesterSleepsIn

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #6 on: 1 Feb 2018, 01:00 pm »
Interesting thread. I hope it continues.

I have S100s and SP100s. The S100s will need upgrading someday but I’ll have to rely on the talents of others since the work is beyond my skill set ... at least I think it is.

I presume you know about the Yahoo Spendor group. If you don’t, you should join. A great bunch of very knowledgeable people including a few Former Spendor engineers always willing to assist:
https://groups.yahoo.com/neo/groups/spendor/info?referrer=tannoy

Looking forward to reading more,
Lester

atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #7 on: 1 Feb 2018, 02:39 pm »
Lester-- 

I do belong but haven't been there in quite awhile.  I'd be surprised if one of the old Spendor hands hasn't tweaked their crossover. 

Spendor Classic folks might also help me with another question re: proper polarity of the drivers. 

Thanks for the encouragement and the reminder!

--Rob

rollo

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #8 on: 1 Feb 2018, 03:54 pm »
   I would not go down that path. I would go listen to the latest Spendors instead.


charles

Tyson

Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #9 on: 1 Feb 2018, 04:09 pm »
Upgrading the crossover parts is an excellent idea.  Caps have the biggest change on the sound.  One other thing you might do is look at the inside of the box and see if it's well braced.  If not, use the opportunity to add some braces.  The other option is to use No Rez that Danny sells on the GR Research site.

LesterSleepsIn

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #10 on: 1 Feb 2018, 05:17 pm »
   I would not go down that path. I would go listen to the latest Spendors instead.


charles

Charles,
You have apparently underestimated the sincere and long lasting love and affection the true believers have for the 'big box' Spendors. (No shade being thrown at the new Spendors, which are terrific.)
Cheers,
Lester




atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #11 on: 1 Feb 2018, 05:53 pm »
Lester--

I couldn't agree more.  There is a review of the S-100s somewhere online.  You may have seen it?  At the end of the review the reviewer recounts being in a position he had to sell his.  He said he sat on the curb and wept as the speakers drove away...   :cry:

Although 'just equipment' some of that equipment does form a profound emotional connection that cant really be explained, doesn't it? 

I will forever miss my Vandersteen 5As and could never see selling off my old Dyna ST70 or my Mac MC275.  Meanwhile there is a lot of stuff (some very high-end) that I don't miss in the least.   

atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #12 on: 1 Feb 2018, 06:03 pm »
Hi Tyson--

Thanks for the encouragement.  I agree passive parts upgrades can do wonders.  Its a bit tricky with a speaker that you really love.  It would be a disaster to "improve" them onlu to screw up the quality that makes them so endearing.  So caution is in order. 

I have considered cabinet tweaks.  But did that in the past to an old pair of Klipsch Cornwalls and something was missing after that.  The speakers sounded more sterile and lost warmth.  Not the direction you want to go with a horn.  I can only imagine that Klipsch voiced the speakers with the cabinet resonance in mind. 

I fear cabinet tweaks would have a similar negative affect on the Spendors in that they adhere to the BBC approach of "tuning" cabinet resonance as opposed to trying to eliminate it. 

atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #13 on: 1 Feb 2018, 06:25 pm »
Sorry! 

Missed one component in the crossover.  There's another resistor that was hidden in the shadows last night.  It looks to be in series with the resistor listed above. But its smaller, has a black cover and looks like it might be a wirewound.  I can not see a wattage on it or a brand.  Can see three lines of print.  First line is 58 ER, middle line is 33R  J (indicating 33 ohm @ 5%) and bottom line is 8843.

avahifi

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Re: Request for Advice on Upgrading Spendor Crossover
« Reply #14 on: 1 Feb 2018, 06:28 pm »
Replacing capacitors?

First thing you need is a multimeter that measures capacitance!

The value of a capacitor is NOT the number printed on the case.  It is the value it actually measures.

Got 10% tolerance 1 uF  capacitors?  Then they can be anything from 0.9 uF to 1.1 uF out of the box.  Got one in each of a pair of speakers?  Then there could be a 20% difference between the two.  Can you hear that?  Sure.

So first note the printed value on each capacitor you want to replace.  Then have enough of the replacements on hand so you can measure each and find new ones within 1% of the proper needed value.  If you can’t come that close, then at least find matched pairs, one for each channel, if you want each channel to sound the same.

Having the correct value, tolerance, and type of capacitor is much more important than boutique capacitors that have not been selected for tight tolerance and channel to channel matching.

This info applies for parts replacement in audio electronics too of course.

Frank Van Alstine

« Last Edit: 1 Feb 2018, 09:12 pm by avahifi »

atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #15 on: 1 Feb 2018, 06:40 pm »
Hi Frank --

Thanks for the encouragement on good practice.  I've got a good Fluke that does capacitance so definitely will follow thru with what you're saying. 

--Rob

Jeff

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #16 on: 2 Feb 2018, 06:08 am »
How did I evolve to this system?

Makes sense, and thank you for sharing, but I was more interested in how/why you went from the stock or modified 5As to the S100.

Quote
Schematic

Great.  I look forward to helping :D

Quote
Did I update and bypass the caps?

No perceivable shortcomings?  No two steps forward, but one step back?
 
Quote
Conflicts?  I'd rather say some of my stated needs engage in healthy competition. But thats how we'll get to a robust and balanced solution.  Besides seems like the most efficient way for all the fine folks here to understand where I wanna go with this.  C'mon buck up!  We can do this!  :lol:

 :icon_lol: I'm not quite sure I follow... :scratch:  In any event, you mentioned budget, fit it all on the board, diminishing returns, etc...  In the same post, you also say that you are after "improve the definition, detail, openess, spaciousness and imaging without damaging the listenability, body and smoothness....picking up the sweetness, body, tone and texture but avoiding the closed-in, lack of detail, lack of dynamics..."  That is a pretty damn tall order :o  And just when I thought you had asked for it all, you deliver the coup d'etat!  "I would like to find the most-leveraging improved passive components to achieve this"   :lol: indeed!

I hate to say it, but the parts that yield the greatest application specific delta (what you are asking for), will neither be cheap, nor fit on your board.  Further, such a golden recipe is unlikely to come from the speculation and debate of hobbyist on an audio forum.  No expert would be 100%.

The solution is simple.  You are merely trying to please yourself.  You alone will know when you are there.  Much R&D would get you there, but it would be expensive.  I believe you would consider this a waste of money.  I consider it buying an education.  I think we can both agree this course of action is prohibitively expensive.  I am here to decrease the price of your education.  If you let me. :D

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Budget  I would say less than $500 unless someone is really persuasive re: the next big leap is just another hundred away...

I'd say that is a healthy outlook, and budget.  Even though we do not know much about the XO yet.

Quote
How did I arrive at my Strawdog   Obsessive review of posts just like this one, going back to 2005.  And put through my particular screens: looking for where the diminishing return curve flattens; avoiding anything called etched or detailed or fatiguing; trying to triangulate from many opinions something that conforms to how I hear; knowing that striving for the nth degree of detail or transparency often works at odds to musical and satisfying (as my journey with electrostats and solid state taught me well); not needing the BEST! as there is no best, only what works with my ears and my system.

Armchair quarterbacking will waste your money faster than...  I find most audio forums contain 50+% misinformation.  Much less being able to derive diminishing returns, etc...  "The best" is application specific, and subjective....what could go wrong? :roll: :icon_lol:

Quote
Measure the Inductors? Hey you didnt even tell me I needed inductors yet!

One of a few early observations.  Any cored inductor working above 300Hz, and definitely above 500Hz, are working against everything "you" are attempting to do.   I do not want to put the cart before the horse, but it was an opportunity to kill to birds with one stone.

Quote
Can I measure them?  No advanced weapons here, but do have a good Fluke VOM and an ammeter.

You could, but not with a VOM.

Quote
Hate to be without the big spendors.  TX is so far away!

You are going to have to sacrifice somewhere :cry:

BTW, all dry paper caps contain wax.  And, I would not recommend the M-resist for your application.

If you would still like my recommendation, and you are drawing up a schematic...  Use a small neo magnet to check all your current resistors for magnetic end caps.  Also check your BP hardware.

Jeff

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #17 on: 2 Feb 2018, 06:35 am »
I presume you know about the Yahoo Spendor group. If you don’t, you should join. A great bunch of very knowledgeable people including a few Former Spendor engineers always willing to assist: https://groups.yahoo.com/neo/groups/spendor/info?referrer=tannoy

Great advice.

I would not go down that path. I would go listen to the latest Spendors instead

You missed the part on diminished returns.

One other thing you might do is look at the inside of the box and see if it's well braced.  If not, use the opportunity to add some braces.  The other option is to use No Rez that Danny sells on the GR Research site.

While this is general good advice, it will not help this speaker/desired results/budget/etc...  BTW, I consider it poor form (or poor forum :icon_lol: :wink:) to recommend a competitors product in my circle :nono:

Jeff

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Re: Request for Advice on Upgrading Spendor Crossover
« Reply #18 on: 2 Feb 2018, 07:57 am »
Quote
First thing you need is a multimeter that measures capacitance!

I do not find handheld multimeters all that accurate.  But, low price has made them practical.

Quote
Then have enough of the replacements on hand so you can measure each and find new ones within 1% of the proper needed value.

If you are using any film caps selected for their superior sonic character, that would be silly expensive, and unnecessary.  I would have some place like Sonic Craft :oops:...match them as tight as I needed them.  They likely match ESR as well, and have a large enough inventory to pull custom targets.

Quote
Having the correct value, tolerance, and type of capacitor is much more important than boutique capacitors that have not been selected for tight tolerance and channel to channel matching

I find this potentially misleading.  Tolerance means nothing if the absolute value is already known.  Since capacitors are timing devices, and rotate phase, matching goes without saying.  In electronics, operating voltage, operating temp, ripple rejection, ESR, resonance, DA/DF, etc...are a given.  Get that wrong, and it will not work long if at all.  Speakers will accept virtually any cap that is non-polar, and at least 50-100V.  If "boutique capacitor" means a capacitor purposed for its sonic character, I find that first and foremost.  Otherwise, why would one replace perfectly good film capacitors?     

Quote
This info applies for parts replacement in audio electronics too of course

I would say it is more important.  With speakers, drivers commonly vary from right to left more than 10% in many respects.

atkinsonrr

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Re: Request for Advice on Upgrading Spendor Crossovers
« Reply #19 on: 2 Feb 2018, 08:28 pm »
@ Jeff

The reason for selling the 5As was they couldn't fit into my lifestyle.  I move a lot, often overseas.  The system I have right now is right at the limit of what I feel can come with and fit into small digs if I relocate for a year or so.  This is timely discussion, because I am learning I may need to move overseas again, within a few months.  This elevates the importance of my objective of fitting upgraded parts into the speaker cabs (I may have given the wrong impression before when I said "on the current boards").

When I did the modest cap upgrade, I didnt perceive any downside at all.

Per your suggestion, I checked everything with a magnet. Magnet definitely attracted to the resistors.  The only thing else on the board that responded was the frame on the one large inductor and the nuts and bolts holding all the inductors to the board. The binding post hardware was fine.

On your confusion about my needs seeming unreasonable, conflict vs compete, or other non-audio stuff, I PM'd you. 

Here's that schematic. Ugly but (I think) accurate!  The inductors I simply showed as boxes.  Lo-Freq at top, Mid-Range in middle and Hi-Freq at bottom.  Binding posts (IN) at right and (OUT) to drivers on the left.  The S100 is (from factory) tri-wireable, so each speaker has 3 pairs of binding posts leading to a separate circuit on the crossover.