OEM x overs and realistic component upgrade

[Alexander]

With in the confines of retaining the factory xo boards of the 1985-mid 90's era ( Quartet, forte and Chorus family's) what is a realistic limit to upgrades. Are the factory inductors/resistors left on the board going to dictate what should/should not be used? We see  Dayton, Solen & SoniCaps often used here but is this really all that is needed? Would the leftover components keep from benefiting going to say Jupiters, OK maybe a bit much there but you get the point.

[CECAA850]

Personally I see no reason to replace anything but the caps.

[Alexander]

2 minutes ago, CECAA850 said:

Personally I see no reason to replace anything but the caps.

 

After re reading my OP I guess I wasn't too clear about that. I was meaning just a re cap, leaving the remaining factory parts in place.

 

[CECAA850]

Just now, Alexander said:

I was meaning just a re cap, leaving the remaining factory parts in place.

I just did that on a set of H2s.  I really don't see the need to replace the coils and autoformers as they won't wear out.

[Schu]

All capacitors sound the same... just like all amplifiers.

 

Remember these famous last words... if you can't measure it, it doesnt exist.

[Schu]

And Vinyl is a horrible 10bit low resolution dead technology.

[Dave A]

Good hi spec polypropolene caps like Dayton work just fine and are cheap and available down to 1% tolerance. If you like to introduce distortion that is preferable to your ears you can spend gobs of money and get looser tolerance designer caps and fine tune it to your tastes but be prepared with your wallet. Erse is good too just make sure to order what is in stock if you don't want to wait for parts. I lean towards wanting to hear what I would at a concert and those people don't use $200 2uf caps to produce what you hear so neither do I.

[Deang]

So, a capacitor with 1% tolerance will have less distortion than a capacitor with 10% tolerance? Why is that?

 

Sounds like you’re an expert when it comes to expensive capacitors. Any chance you might know why they cost so much?

 

What expensive caps have you tried?

[Deang]

At any rate, since people typically spend around $800 on those speakers, they aren’t likely to go wild on the networks. 

 

There isn’t much real estate on the PCBs, so you’re definitely limited on what you can use. Lately I’ve been using Jantzen z-standard on most of them. I use the Dayton 1% capacitors in series with the horn when I do RF-7s. A Jantzen CrossCap goes in the LCR. I use Mills resistors in all builds - unless I can’t source the value(s).

 

These are decent parts, and worlds better than what’s in them now - and with a little bit of coaxing, they fit - and everything goes back together the way it’s supposed to, which is nice. 

 

 

[Dave A]

Nope not an expert but in talking to some who I do believe to be expert and who use methodology to arrive at their conclusions I regard highly I have arrived at some conclusions. I get out the trusty old B&K 885 and measure the old capacitors I remove with high ESR and measure the new ones and hear the difference and see the ESR at like .001 compared to typically .2 to .5 or more. I see the specs on the expensive ones that are not any better than what I measure with Erse and Dayton and can't see any reason to argue with the advice I have been given. You have my attention so please explain what the difference is that would compel me to spend much more to rebuild a crossover.

[pzannucci]

7 hours ago, Dave A said:

Nope not an expert but in talking to some who I do believe to be expert and who use methodology to arrive at their conclusions I regard highly I have arrived at some conclusions. I get out the trusty old B&K 885 and measure the old capacitors I remove with high ESR and measure the new ones and hear the difference and see the ESR at like .001 compared to typically .2 to .5 or more. I see the specs on the expensive ones that are not any better than what I measure with Erse and Dayton and can't see any reason to argue with the advice I have been given. You have my attention so please explain what the difference is that would compel me to spend much more to rebuild a crossover.

I think the point @Deang was making was the statement about distortion.  I think you are really talking a modification from what someone's frequency response intent was was when the speaker was designed.

It's all going to be perception as I might love old dried out caps on a Heresy 1 since I don't like (to me) the shrill K-77 but others turn up the treble.  To each their own.

[Deang]

15 hours ago, CECAA850 said:

Personally I see no reason to replace anything but the caps.

It depends. On older networks, I've seen where the windings can be moved up and down the core. This applies to old T2A autoformers and the low pass coil. The new autoformers are also bifilar wound, and don't look like debris from a bombing run.

[CECAA850]

1 minute ago, Deang said:

It depends. On older networks, I've seen where the windings can be moved up and down the core. This applies to old T2A autoformers and the low pass coil. The new autoformers are also bifilar wound, and don't look like debris from a bombing run.

What effect would the windings moving on the core have on the sound?

 

I agree that some of them are fugly though.

[Dave A]

1 hour ago, pzannucci said:

I think the point @Deang was making was the statement about distortion.  I think you are really talking a modification from what someone's frequency response intent was was when the speaker was designed.

It's all going to be perception as I might love old dried out caps on a Heresy 1 since I don't like (to me) the shrill K-77 but others turn up the treble.  To each their own.

 

  Yes to what makes one happy. I like to fiddle around and achieve a sound that pleases me and not break the bank to do it. I would far rather get basic good crossover components and if I want to go from there change settings on say a graphic equalizer to get that warm fuzzy feeling. Then later I can change it to something else for another type of music. To me Dayton or equivalent caps give me the correct electrical values and then I have gobs of money left over to buy devices that can change the nature of my sound on every speaker I own when I want and how I want. It blows my mind how expensive some of these silly fru-fru caps can cost and then you have something that only works one way on one thing and I bet most of us could not hear the difference in a blind test all specs being equal.

 

  OK we can call it modification from original intent which is a polite way of saying we have distorted the sound from the original intent.  Either one means deviation from design specs. 

[Dave A]

16 minutes ago, CECAA850 said:

and don't look like debris from a bombing run

  How true! I can't believe how crude some of these look.  Crites makes claims that the new transformers have better and more consistent values and I have no doubt he is right.

[pzannucci]

5 minutes ago, Dave A said:

 

  OK we can call it modification from original intent which is a polite way of saying we have distorted the sound from the original intent.  Either one means deviation from design specs. 

Not to split hairs but each speaker is not designed to a .5db tolerance from reference so they are all distorted by your thoughts.  I'd like to think of distortion as the components adding, modifying, or detracting from the input signal, individually from their design and tolerance intents.  Not necessarily as a whole as we know most of these speakers are not perfect matches to the pair or others off the production line.  Perspectives.

[Deang]

2 hours ago, CECAA850 said:

What effect would the windings moving on the core have on the sound?

 

I honestly don't know.

 

 

 

[Deang]

Never mind.

[Dave A]

On 2/9/2018 at 8:03 AM, pzannucci said:

Not to split hairs but each speaker is not designed to a .5db tolerance from reference so they are all distorted by your thoughts.  I'd like to think of distortion as the components adding, modifying, or detracting from the input signal, individually from their design and tolerance intents.  Not necessarily as a whole as we know most of these speakers are not perfect matches to the pair or others off the production line.  Perspectives.

Yes and you add the flavor you like to the mix.

  In machining there is a phenomena called tolerance stack up. What it means is that there is a design with basic accuracy specs. At every step of the machining process there are inherent deviations from out of center line end mills in tool holders to slack in xyz servos to deviance from true diameter specs on cutters. All these and more not mentioned add up and if they get out of hand will cause a part that will be rejected. I find this is true in all things and then you have to set the base line that can be met for purpose and cost of production. What I try to do is eliminate some of this by using good tolerance caps and match them as close as my handful of parts allows for speaker pairs and I always do both crossovers at the same time. The rest of the components stay as they are since matching drivers could get expensive quickly and I figure the best bang for the buck is going to be a crossover refresh. I fully understand nothing is perfect but the closer you can get to design parameters the better I presume unless engineers just pull numbers out of a hat for the heck of it and somehow I don't think this happens.

[Alexander]

Here is one issue trying to move up the proverbial ladder of caps , in this case we need 4x 2.0uF and 2x 1.5uF for the pair of networks for the forte II.  Now 1.5uF values aren't a problem as most manufactures offer them but they only offer 2.2uF and not 2.0uF so instead of getting a total of six caps we now need to purchase ten at the what can be much higher prices per cap to get our ~2.0uF values.