'76 La Scala - ALK Universal to Type A???

[boleiro]

So I've been listening to my 76 LS-BB's for almost a year now and I am still in love.  But, I'm back!  I'm hoping to get some insight and experiences from those who have gone from some ALK Universal X0's to Type A's. I've seen a lot of threads here asking for opinions moving from the Type A and Type AA to the ALK's, but nothing about moving in the opposite direction.  Though, I'm sure it's been discussed:).

 

My La Scala's came to me with DIY ALK Universal Crossovers with all stock drivers (I attached the schematic matching my XO's).  I'm a tinkerer, so the fact that I've left these a lone for a year is saying something.  Although, I did start looking into upgrading the caps.  the Caps aren't anything exciting to me, they seem to be the standard faire for the basic ALK universal XO from pics on the web; solen 39uf, harmony bypass caps and hovland musicap 6.2 and 2.2uf.  I thought improvement could be had, real or placebo, with some "better caps".  But, after reading up on what caps others have used for their LS's, I began to see mention of the Type A crossover being a great fit for lower volume listening and I started feeling the desire to hear my LS' in their original state, factory fresh.  I listen at pretty low volumes, rarely going above 90db.  Maybe a Type A XO would suit my listening habits better?  My system is a 2 channel set up with a lower powered tube amp and I listen to vinyl pretty exclusively.  I rarely get to see the meters dance as i struggle to hit even 1 watt.  The LS' are so efficient!  

 

So I have started to think about building some Type A crossovers.  Anyone have any thoughts on what would I be giving up and what would I could be gaining by going back to the Type A's?  Or should I just upgrade the caps on my current XO's?

 

 

[OO1]

I would go back to an original set of klipsch XO AA  ---as it adds the zener diodes to protect the tweeter

[boleiro]

Hey Randy… I thought about the AA, but aside from the tweeter protection what is the advantage of tha AA over the A.  I’m not really worried about my tweeters as I listen at pretty reasonable volumes.   I know, accidents happen, but I like the simplicity of the circuit.   Would it be wrong to do the AA without the Zeners?

[Honeybadger]

Seems like a step in the wrong direction, but let your ears be the judge.

 

I have seen several posts where someone preferred type As with set amps in the proper environment.

 

What I don't know is a lot.   HB.

[Panelhead]

  I would recommend replace the tweeters first. The B&C DA-120 and a new horn should transform the LS. 

  Then revisit the crossovers after another year of listening. 

  BTW, the caps used to build the ALK Universals seem like good stuff.

[boleiro]

Honeybadger… I’m inclined to agree with you after further research and guidance.  I also read a few glowing reviews from those who preferred the type a for set amps.  It got me thinking but I feel I am back on track and will look to build up some Type AA xo’s.   
 

Panelhead, I swear I talked to someone on this thread last night about replacing the tweeter with the DaveA SMAHL V2 horn and DE120 drivers.   I like the K77 a lot.   Do you really feel the DE120 would make that big of an improvement?  My only fear on this move is that the main reason I want to replace the ALK xo is to actually hear what my LA Scalas sounded like  new.  I have never heard the the La Scalas with anything but the ALK crossover.  Really wanted to hear the original character of the speaker.  Don’t get me wrong, I’m very into the idea of upgrading the speaker and even have a pair of the DE120s in my eBay watch list now.   It’s going to happen.  
 

appreciate the help.   My list of mods for the la Scalas is growing by the day! 

[OO1]

On 8/6/2021 at 7:50 PM, boleiro said:

Hey Randy… I thought about the AA, but aside from the tweeter protection what is the advantage of tha AA over the A.  I’m not really worried about my tweeters as I listen at pretty reasonable volumes.   I know, accidents happen, but I like the simplicity of the circuit.   Would it be wrong to do the AA without the Zeners?

you can bypass the zener diode,   I would advise on purchasing a set of AA's   , since thy XO's were tested by klipsch --- you can  then purchase klipsch Caps from @JEM Performance   to renew the aged capacitors ---VIP  these  factory parts will restore the klipsch  sound ,  for purists , and JEM is the Sole USA supplier 

[karlson3]

Re: DE-120 - is there a little cheap plastic  K77/T35  horn to fit that driver?

 

Here's an A configured network battery biassed before mounting the 9v battery holder.   IIRC DJK (R.I.P.) said the AA tweeter section could be converted into an "Acoustic Butterworth" with a 1uF cap spanning its two caps.

 

 

[Curious_George]

When I first got my LaScala's with AA's, I transitioned from 1979 Heresy's. The Heresy's sounded great, but I always loved the way the LaScala's looked and sounded (from what I could remember listening to them years ago in my youth). The drivers all looked to be originals and in good shape. Close serial numbers on the driver pairs. The crossovers had the caps changed and were mis-matched with different brands / types. One crossover had a "brown drop" (an orange drop look alike that was brown) and the other had a cheap yellow Mylar cap. I changed the caps to all one brand and type for consistency. 

 

My first listening impressions were underwhelming... My main source is a CD player. As much as I am an analog guy, I hate pops and clicks from vinyl. Very forward midrange, rolled of high frequencies and low bass output. These were in the corners of a small living area, out from the wall about 1 to 2 feet. The Heresy's actually had better bass, but not by much. I switched the midrange from tap 4 to tap 3 (making the cap change) and that helped a bit, but still underwhelmed.

 

Apparently that is the way they were designed and people either fall in love with them or modify them. I fell in love with them and modified them, and love them even more now. Nothing like a full horn speaker system. They are an acquired taste though, not for everyone. 

[boleiro]

8 hours ago, karlson3 said:

Re: DE-120 - is there a little cheap plastic  K77/T35  horn to fit that driver?

 

Here's an A configured network battery biassed before mounting the 9v battery holder.   IIRC DJK (R.I.P.) said the AA tweeter section could be converted into an "Acoustic Butterworth" with a 1uF cap spanning its two caps.

 

 

You got me Karlson, what is an acoustic butterworth filter and what’s the benefit?

[boleiro]

Hey George, 

 

you kind of nailed the whole point of this thread!  I love the Klipsch sound.  I know a lot don’t, but I’m hooked on horns and Klipsch is my new home.   I’m a late comer though, got a pair of heresy II’s  couple of years ago after hearing so much about how well horns go with tube Amps.   Those  heresys with my SET amp is pretty awesome.   I moved on to the La Scalas shortly after and I am even more in love with the Scalas.  They sound awesome with the ALK xo’s… amd it’s not that I want to change the sound or that I’m looking for something. Different than we say, but I just can’t shake my curiosity of what the stock Type AA will do.  Do my La Scalas sound anything like they intended to or does the ALK completely change the sound characteristics?  So I started a thread to find out if it would be a worthwhile venture… would the difference be anything special? 
 

got some good answers and some ideas.   btw… clean your records!  No pops and clicks here:)

[Woofers and Tweeters]

Love my ALKs. They are a real move in making my Belle sound a lot better / cleaner than stock. You mentioned HII. I rebuilt he x overs in a pair not too long ago. Again, they sound better than ever. 

[pcbiz]

1 hour ago, boleiro said:

Hey George, 

 

you kind of nailed the whole point of this thread!  I love the Klipsch sound.  I know a lot don’t, but I’m hooked on horns and Klipsch is my new home.   I’m a late comer though, got a pair of heresy II’s  couple of years ago after hearing so much about how well horns go with tube Amps.   Those  heresys with my SET amp is pretty awesome.   I moved on to the La Scalas shortly after and I am even more in love with the Scalas.  They sound awesome with the ALK xo’s… amd it’s not that I want to change the sound or that I’m looking for something. Different than we say, but I just can’t shake my curiosity of what the stock Type AA will do.  Do my La Scalas sound anything like they intended to or does the ALK completely change the sound characteristics?  So I started a thread to find out if it would be a worthwhile venture… would the difference be anything special? 
 

got some good answers and some ideas.   btw… clean your records!  No pops and clicks here:)

 

It's definitely worth your time to experiment. Most likely you'll prefer the ALK, but understanding history is a reward in itself.

 

I've listened to a number of vintage La Scalas on Youtube. Although not a perfect evaluation, I am able to assemble an audio composite of the original La Scala sound. The original La Scala is not as refined as La Scala II, but a modded first generation La Scala can definitely get close to the La Scala II sound. Many even prefer a modded original La Scala to La Scala II.

[boleiro]

4 hours ago, Woofers and Tweeters said:

Love my ALKs. They are a real move in making my Belle sound a lot better / cleaner than stock. You mentioned HII. I rebuilt he x overs in a pair not too long ago. Again, they sound better than ever. 

I love mine too!  Very happy with the ALK's... the only reason I want to try the AA xo is to see what the original sound is. If it makes sense, I have no baseline for my La Scalas.  I have.never heard any other La Scala in person.  So I just wonder.  My heresy's are stock and they sound awesome, no plans to upgrade those until needed.  Myabe I'm just trying to justify a project... when I already have a few in in the queue; Refinish the La Scala's, Paint the Listening Room, finish the Brick Pizza Oven... or maybe I should spend my money on a ton of records.  It would suck to spend money only to switch it right back to the ALK's.  But I'd know:).  

 

Thanks all... food for thought and I really appreciate your experience!

[Tom Mobley]

I've built/used several sets of the ALK universals.  IMO you're going to have a tough time finding anything better.  real tough.  I need to build another set for my '60 Khorns.

[KT88]

It's just my two cents. I bought the ALK universal network 16 years ago for my 1977 Lascala. I was not satisfied with it. It sounded "clean" but not so musical, I could hear the tweeter separately from the midrange when there was pink noise. Then I bought the AA network from Crites, which can be plugged into Type A. I like AA better, A was good on a 300B and a Leak Stereo20. But AA gives more definition. A is warm but AA gives me more speech intelligibility without sounding "cold" like ALK Universal does to my ears.
AA definitely sounds best on my MC275.
A is for low volumes, AA for soft to adequate volumes. The coherence is fantastic with AA.
About the tweeter, I had a CT125, that was more "hifi" sound. But the K77 does a much better job of a "unified voice". It's less hifi but more Klipsch with great timing and authority of sound, even if the K77 hisses a bit depending on the recording, I won't change it. I cannot speak about the newer iterations of tweeters mentioned here but if I were you I would build up everything Xover etc. before I would change the in my view excellent matching original tweeter. BTW Polyester caps do the magic in my view on an AA network as the original canned caps were also polyester types. The „Q“ of this caps seem to match the horns very good and it is certainly no coincidence that even the most modern, highly praised Klipsch Heritage speakers have these yellow polyester caps, as can be seen in photos on the Internet. For me the change to such a type was definitely an improvement over the whole freq. band after I had Sonicaps before.
With the AA crossover it is definitely the much nicer sound when the Zener diodes are not in the circuit. It's only a protection for very loud signals or when a transistor amplifier makes loud clicks when switched on and off. Type A is 6 Db to the tweeter, type AA is 18 Db but still inherent.

[Curious_George]

22 hours ago, boleiro said:

Hey George, 

 

you kind of nailed the whole point of this thread!  I love the Klipsch sound.  I know a lot don’t, but I’m hooked on horns and Klipsch is my new home.   I’m a late comer though, got a pair of heresy II’s  couple of years ago after hearing so much about how well horns go with tube Amps.   Those  heresys with my SET amp is pretty awesome.   I moved on to the La Scalas shortly after and I am even more in love with the Scalas.  They sound awesome with the ALK xo’s… amd it’s not that I want to change the sound or that I’m looking for something. Different than we say, but I just can’t shake my curiosity of what the stock Type AA will do.  Do my La Scalas sound anything like they intended to or does the ALK completely change the sound characteristics?  So I started a thread to find out if it would be a worthwhile venture… would the difference be anything special? 
 

got some good answers and some ideas.   btw… clean your records!  No pops and clicks here:)

 

The ALK universal will change the way your LaScala's sound. Imagine a "bell curve" from your statistics class (stock LaScala) compared to a flat line (ALK crossover mod). This is just a visual, but the sound is different between the 2 crossovers. 

 

The A and AA crossover will let more of the midrange (high & low crossover points) bleed into the music spectrum. The A, AA and ALK are all 18dB on the tweeter, but slightly different the way they are derived. We all hear differently (physical & psychological factors) and this is the major reason someone may prefer one crossover to another. 

 

It should not be too hard to convert your ALK's to an A or AA. Do it and see how it sounds. The Zener diodes don't do anything unless you are driving the speakers hard. They are invisible at mid to lower volumes. 

Edited August 9, 2021 by Curious_George

[KT88]

I agree with everything, but I have found that the Zener diodes take away some of the silkiness and colour of the sound, even at low volumes. But it's no effort at all to try out both settings personally.

[Marvel]

Just wanted to point out that the ALK has a swamping resistor in the circuit, which helps provide a more even load for lower powered tube amps. You will just have to change to an A/AA to see if you like it better.

[boleiro]

3 hours ago, Curious_George said:

 

The ALK universal will change the way your LaScala's sound. Imagine a "bell curve" from your statistics class (stock LaScala) compared to a flat line (ALK crossover mod). This is just a visual, but the sound is different between the 2 crossovers. 

 

The A and AA crossover will let more of the midrange (high & low crossover points) bleed into the music spectrum. The A, AA and ALK are all 18dB on the tweeter, but slightly different the way they are derived. We all hear differently (physical & psychological factors) and this is the major reason someone may prefer one crossover to another. 

 

It should not be too hard to convert your ALK's to an A or AA. Do it and see how it sounds. The Zener diodes don't do anything unless you are driving the speakers hard. They are invisible at mid to lower volumes. 

This!  thanks again George... never thought to convert the ALK's to AA's.  probably because I didn't know you could... they seem very different across the board.  If this conversion in fact a simple task then this would be great.  Any resources on the conversion itself?