Heresy "E" Crossover Replacement

[pkeller]

Reposted from "P-Trap" topic.

OK, I finally got around to swapping the stock Heresy type "E" crossovers with the new ones mentioned a couple posts above. My Heresy's are 1978 (alnico) vintage and have had the "P trap" installed for the past several months. I have been changing other things in my audio system recently (amplifier mods), so I had to get familliar with the sound before I could make any meaningfull comparisson of the two crossovers. Now the results:

First impression (installed 5 minutes ago) is that the tweeter has more detail and delecacy. There is a bit more transparency and detail across the entire audio range. Bass is more controlled and a tad stronger. Imaging and dynamics are enhanced.

Now the down side. The midrange, while cleaner, is slightly too strong. Remember that this system does include the P-trap. This may be corrected by a simple relocation of the squawker "-" wire to the #1 tap on the autoformer, rather than the stock #2 location. This would lower the mid horn -3db and probably be about right. To be fair,the new caps have not had a chance to settle in and the excess mid might take care of itself in time. It's not too far off as it is, but could be better.

Over all, the new crossover has much more potential than the stock unit. The much larger inductor and Zen polypropylene film caps are clearly superior to the 23 year old components they replace. As for the UTC autoformer, It's about the same size as the stock unit. Al Klappenberger made some measurments of it a while back and found it better, so I used it.

I have a photo of the new crossovers, but I'm having trouble attaching it to this board. Can anyone tell me how?

As I type this, the sound comming from the Heresy's seems to be getting better. Even more detail. Either the mids are settling down a bit or the highs are getting stronger and more in balance with the mids and lows. Just for refrence, Im using modified Heathkit EA-2(12 watt 6BQ5/EL-84) amplifiers. Efficiency is about the same as before.

I won't be changing back to the old networks. I have about an hour of listening time now (I type slowly) and the mids are getting to be about right. Detail and transparency is increasing as time passes.

I'm Jazzed.

Hope all this helps.

Paul Keller

[pkeller]

I have several hours on the new crossovers now. Mids have gotten even more in balance with the tweeter and woofer. I was reminded by another BB participant that if the squawker neg. was moved to another tap on the autoformer, it would require a cap value compensation due to the inductance change. There is no need anyway since squawker strength is no longer an issue.

The Heresy's have gotten much more depth and clarity to their image presentation. High frequencys are more extended and delicate when called upon for detail. I think the stock oil caps were holding them back from the upper reaches a bit. The bass has an effortlessness that it didn't before. The transient bass response, like when Ray Brown plucks a string, has more vibrancy and immediacy than before. The strength of the bass is about the same, just quicker.

This crossover system would probably mate well with SET amplifiers, as it is "very" revealing. 30 year old solid state amplifiers, like a Dynaco ST-120, would be awfull. You would hear all of that bench grinder like character (yes, I have one)(in the closet).

The next mod I'll try will probably be a bypass of the Zen caps with Northcreek Harmony .1uf caps. This only represents an insignificant 5% change in cap value and is supposed to allow even more detail. I'm going to wait a while so I can get used to the existing network though.

Paul Keller

[JLOUNDER]

Excellent, I was hoping you would get them installed soon so I could find out if it would be worthwhile for me to upgrade. I do have one request if I could impose. Where did you order the Solen Heptalitz inductors from? I haven't been able to find them on-line, except straight from Solen. Keep us posted on the new and improved crossovers, after they've settled in some more.

BTW I am using Fisher Model 30A Monoblocks that use EL84/6BQ5's that have been modded some. I think they drive the Heresey's just fine.

[pkeller]

The Solen Heptalitz inductors for the "P trap" was purchased from Solen. It was a Canadian address that I cannot find right now. It was in the archives in a post by Al Klappenberger. All caps were Zen and purchased from Northcreek. The autoformer was from Universal Transformer Company (UTC). The large network inductor was Madisound Perfect Lay air core 14ga.

As I listen to the Heresy's more closely, I'm finding that there is a mild harshness in the upper mid that does not blend well with all types of music. I am being very picky. There is no question that spaciousness and detail is much better with the new system. You can really "feel" the ridges of Martin Taylor's finger prints as he plucks the strings of his guitar. To go back to the stock network would sound a tad confined and thick by contrast.

In reading Northcreek's information about bypass capping, It looks like it may work well to tame the mild harshness while retaining the clarity. The single bypass cap would be added to the 2uf cap beween the + terminal and the autoformer.

I mis-wrote in the above post regarding the Harmony bypass caps. I should have said "Crescendo" .1uf 800v cap. I have yet to try it though. All values were stock. Hope this answers what you need to know.

Paul

[pkeller]

Here is a photo without the P-trap installed.

I hope this attachment works.

If it fails, send me an e-mail address and I'll bypass the BB.

Paul

[JLOUNDER]

pkeller

Thanks for the info, I found the Solen website and will have to order a catalog as well as order the parts. The attachment worked fine, it looks fairly straighforward from the pic. I read on the North Creek website that they recommend a bypass cap. It sounds like the cure for what you are experiencing. Although the caps have yet to really break in, so time may tell. Keep me posted on your results. I'm going to get busy ordering some parts. Thanks again.