Dual Phase Plug K55 V/Soldered Lug Heresy Explanation Please

[rotobadger]

I recently committed to purchasing a beautiful pair of 1981 Heresy HWO. Just gorgeous. The only thing they'll need is a recap. Fortunately, very straight forward project even for a dunce like me.

So, I keep reading about the "coveted" Dual Phase Plug K55 V soldered lug driver. I have been unable to find any description of what this actually MEANS. Why is this considered desirable? Is the sound considered to be superior in some way?

Thanks for any explanation you can provide.

 

[David D]

I’ve run across the same thing and would be very interested as well. I just acquired a beautiful pair of 1978 Heresy HWO’s as well. I swapped the tweeters out for a set of Dave’s SMAHL’s and am very pleased with the upgrade.

 

[cecaa850]

The soldered lug is an easy way to identify this driver as opposed to the push pin type. I believe that the phase plug was improved, and these are fairly universally accepted to be the better sounding driver of the 2 styles.

 

[rotobadger]

The soldered lug is an easy way to identify this driver as opposed to the push pin type. I believe that the phase plug was improved, and these are fairly universally accepted to be the better sounding driver of the 2 styles.

Thanks for the reply. I'm still not sure I understand. What is the soldered lug? Where is it located on the driver? And, why is this an improvement?

I've even googled for pictures (which as yielded results) but still don't know what I'm looking for or how to identify a soldered lug. I know its soldered vs spring loaded but where is it?

 

[cecaa850]

Thanks for the reply. I'm still not sure I understand. What is the soldered lug? Where is it located on the driver? And, why is this an improvement?

I've even googled for pictures (which as yielded results) but still don't know what I'm looking for or how to identify a soldered lug. I know its soldered vs spring loaded but where is it?

The wires are attached to the driver with solder on this driver. On the other driver the wires are attached with push terminals (or possibly spades). The way that the wires hook to the driver makes no sonic difference rather is an easy way to tell if you have the more desireable driver.

 

[rotobadger]

The wires are attached to the driver with solder on this driver. On the other driver the wires are attached with push terminals (or possibly spades). The way that the wires hook to the driver makes no sonic difference rather is an easy way to tell if you have the more desireable driver.

That’s helpful thanks much

 

[Audible Nectar]

OK, wrong guy to answer best, but here is the "gist":

The solder terminal K55V (only produced for a couple of years, around 1980-1981ish) is free of "The Glitch" (it's either 6 or 9 kHz, can't remember which) which appears in a substantial percentage of K55Vs of "normal" (read: prior to the solder terminal version in production, those will have the standard push terminals) origin.

That "glitch" clashes against the K77 like a train wreck, especially on certain networks and models where it's worse than some others. If your K55s have that glitch it is AWFUL and will drive people crazy getting rid of it (harsh treble).

It gets complex because a number of "normal" K55s don't have the issue, but a lot of them do, and I will certainly say that this was a large contributor to their rep as a "PA" speaker or "too harsh to handle" . In speakers with replaced networks those can REALLY show that flaw with some cap formulae.

It was a bit of a held secret of sorts on Klipsch Forum, especially before the A55G showed upon the market - people talked about it but tried not to make a big deal over it and cause the drivers to soar to $500 each, LOL. But once I rolled a pair of solder terminal K55 with the dual phase plug/solder terminal (which I bought on forum) into my Belles I became a REAL believer - that the "glitch", if present, is a MAJOR factor in sorta ruining the speaker from a truly hi-fidelity perspective. There's a newer Atlas driver that fixed this too I think, as well as the A55G which is also free of that issue and probably this "drop in driver alternative" best replacement version. But back before those drivers existed it was the "solder terminal" version of that driver that became sought after because it' a smoother driver.

And many still consider this as good of a driver as available, the AlNiCo K55V solder terminal is a pretty good mid driver among ALL of them now out there point of fact, from one who has sought the BEST of that driver as I wanted to keep my cabs original. The only reason I ultimately replaced mine was over a 50-year updating of ALL the innards so I went all new with the A55G. But the K55V solder terminal version is right up there, and oft still the best in many eyes and ears out of these as they really like the character of the AlNiCo, which is notable.

All of that to say you have the "good" version to be sure.

 

[rotobadger]

OK, wrong guy to answer best, but here is the "gist":

The solder terminal K55V (only produced for a couple of years, around 1980-1981ish) is free of "The Glitch" (it's either 6 or 9 kHz, can't remember which) which appears in a substantial percentage of K55Vs of "normal" (read: prior to the solder terminal version in production, those will have the standard push terminals) origin.

That "glitch" clashes against the K77 like a train wreck, especially on certain networks and models where it's worse than some others. If your K55s have that glitch it is AWFUL and will drive people crazy getting rid of it (harsh treble).

It gets complex because a number of "normal" K55s don't have the issue, but a lot of them do, and I will certainly say that this was a large contributor to their rep as a "PA" speaker or "too harsh to handle" . In speakers with replaced networks those can REALLY show that flaw with some cap formulae.

It was a bit of a held secret of sorts on Klipsch Forum, especially before the A55G showed upon the market - people talked about it but tried not to make a big deal over it and cause the drivers to soar to $500 each, LOL. But once I rolled a pair of solder terminal K55 with the dual phase plug/solder terminal (which I bought on forum) into my Belles I became a REAL believer - that the "glitch", if present, is a MAJOR factor in sorta ruining the speaker from a truly hi-fidelity perspective. There's a newer Atlas driver that fixed this too I think, as well as the A55G which is also free of that issue and probably this "drop in driver alternative" best replacement version. But back before those drivers existed it was the "solder terminal" version of that driver that became sought after because it' a smoother driver.

And many still consider this as good of a driver as available, the AlNiCo K55V solder terminal is a pretty good mid driver among ALL of them now out there point of fact, from one who has sought the BEST of that driver as I wanted to keep my cabs original. The only reason I ultimately replaced mine was over a 50-year updating of ALL the innards so I went all new with the A55G. But the K55V solder terminal version is right up there, and oft still the best in many eyes and ears out of these as they really like the character of the AlNiCo, which is notable.

All of that to say you have the "good" version to be sure.

Excellent explanation. This helps me a lot. I really didn’t know what the fuss was but kept reading 1981 was one of the “good” years for Heresy.

Here are a few pics of mine. I haven’t received them yet as the seller will be driving to my city to visit family for Christmas so I have to wait until the 20th of December. Not too far off tho.

As I said, I will be recapping with Sonicaps.

Here are some beauty pics as well is internals. I’m guessing it’s impossible to tell from these pics if these speakers have the soldered lugs but, since it’s a 1981 model (consecutive serial numbers) I’m assuming yes.

Thanks again!

 

[Daveintn]

Great explanation Audible.

Excellent explanation. This helps me a lot. I really didn’t know what the fuss was but kept reading 1981 was one of the “good” years for Heresy.

Here are a few pics of mine. I haven’t received them yet as the seller will be driving to my city to visit family for Christmas so I have to wait until the 20th of December. Not too far off tho.

As I said, I will be recapping with Sonicaps.

Here are some beauty pics as well is internals. I’m guessing it’s impossible to tell from these pics if these speakers have the soldered lugs but, since it’s a 1981 model (consecutive serial numbers) I’m assuming yes.

Thanks again!

View attachment 2685498 View attachment 2685499 View attachment 2685500 View attachment 2685501 View attachment 2685502 View attachment 2685503 View attachment 2685504 View attachment 2685505

Sonicaps had a great Klipsch reputation established for them by Bob Crites. I have had a commercial account there for few years and have watched the price tag explode and never buy them now. They sounded kind of sterile to me last set of crossovers I did and I found the Dayton 1% and Audyn red caps to be more pleasing and a darned sight cheaper. Main thing is to get rid of those old high ESR caps you now have. I have some Sonicap 2uf's I will not be using kicking around if you want to reach out to me.