Heresy I's arrived - WOO HOO! w/Pic of 2nd system

[codhead]

[Erik Mandaville]

Cod:

Yes, I was the one who purchased the parts and schematic from Moth Audio. There are certainly differences between the amp you have and the one I built -- primarily in relation to the PSU transformers and dual filter chokes. I don't have a toroidal power transformer, and mine came with with a single, fairly common variety filter choke. The amplifier circuitry should be the same, however I found some improvements in the overall sound with some small changes to the plate and cathode bias resistors, as well as with the cathode resistor bypass capacitors on the 6SL7.

When I ordered my parts, Moth Audio also no longer had in stock any of the Si2A3 top plates, and so I recieved one that was designed for the 300B amp. This is punched for bias adjustment meters and related potentiometers. I asked that the meters and controls be included, and built this feature into my amp, but found the bias tweak effective over only a very, very small range. So, I took all of that out, and made a screen for the meter holes (which uses the meter mounting hardware on the inside of the chassis)from a metal mesh pencil holder I found at Target. It actually adds more to the retro look of the amp (which I LOVE!)and will provide additional cooling.

The bias potentiometers were removed, and I installed in their place high quality shorting switches to switch back and forth between the speaker outputs of the amp and my headphones. I found this much quieter than just using the headphone jack that came with the amplifier.

I have to say that I really, really liked the Moth with the Klipschorns, and had been useing it in three channel mode along with a Klipsch minibox and La Scala center channel. Since I have been listening to surround sound by way of a Lexicon digital processer, I was very much underwhelmed by the performance of the Moth with the Lexicon. They were not a good match for one another. However, the Moth, along with a preamp I made last year and our Denon, actually is used far more than the rest of our system. It is an incredibly fine-sounding headphone amp, and I use it daily for a couple of hours.

I think the version you have might be a little more quiet in terms of residual power supply noise, but I really love this amplifier. I think it would sound very good with Heresys, so I'm not surprised if you find the two a great match for one another.

Erik

[Erik Mandaville]

Oh, I forgot to mention, Codhead: I think I see an AES or Cary Audio line amp in your system -- or that might be their phonostage. Anyway, I found that the Moth, even thought it has its own volume control, sounds better with some extra gain provided by an active gain stage. It is great by itself, but I find that there is some extra weight in bass response, as well as more articulation or detail in the high end. I also have dual balance controls on my preamp, and I find that they can really be a help with headphones. For some reason, I'm more aware of balance concerns when using headphones.

Erik

[TBrennan]

Cod----Alnico Altec and JBL compression drivers are worth more than ferrites because they're prettier and are of more interest to collectors. I used to have lots of those drivers and I enjoyed just holding them and admiring the Altec Hammertone green and JBL black stove-crackle finishes.

Many Altec users, as opposed to collectors, are fans of the late model ferrite drivers. JBL ferrites use titanium diaphragms and the earlier Alnicos used aluminum ones, that's why the Alnico JBLs sound different than ferrites. And I know guys happily using Alnico-aluminum JBLs and guys happy using ferrite-titanium ones.

There are Altec and JBL folks who think Alnico drivers sound better, there is an opposing viewpoint, but I don't hold with it. And all my current Altecs are Alnico "Greenies".

Anyway Cod if you're interested in this subject there's been lots of talk about it, pro and con, at the Altec Users Forum and the forum at the Lansing Heritage site. Fun reading, at least to idiots like us.

[codhead]

[codhead]

[codhead]

[TBrennan]

Cod----I think the reason some guitarists like Alnico speakers is because they are often malfunctioning and this gives a certain tonal quality.

Alnico magnets are very susceptible to weakening from being driven hard. High currents running through the coil form a field which can weaken the magnet, the result is that the speaker no longer can reproduce high tones as well.

Some folks think that when an Alnico driver is driven to it's mechanical limits it has a softer "stop" than with ferrites and this effects the sound. I dunno.

Some astute folks believe that most Alnico speakers that have been subjected to high stress, and certainly any that have blown, have weakened magnets. One fella that has rediaphragmed scads of blown Alnico JBLs says every single one has needed it's magnet recharged.

Anyway I'm glad you're enjoying your new speakers. The proof of the pudding and all that...

[Erik Mandaville]

Cod: You asked and mentioned:

"Funny you should mention a three channel setup. I was reading the Heresy owner's manual, and Klipsch also talks about using the Heresy as a bridged center channel between two Klipschorns. Is this what you were running? I can remember as a kid, being told by my music teacher that he liked to listen to Wagner on his three channel system, but I've not heard that term used very much over the years."

I had to chuckle when I read this, although not because it's funny but rather because of the forum history on the topic -- using more than two channels for music playback. And you say your music teacher enjoyed listening with a center channel, as well. That does not surprise me

In short, yeah, that's how it started -- first a Heresy in the middle, driven by way of the so-called Klipsch minibox and a dedicated mono amplifier. That has evolved into the use of a three channel digital amp, two 2A3 monoblocks for the sides, and Heresys now being used as the rears; all for a total of 7 speakers, with current investigation into active subwoofers. A Lexicon DC-1 digital processer/line amp is the heart of all of this, and it is what has replaced the little Klipsch 'minibox'. The minibox simply derives a center channel via speaker level signals taken from the right and left amps of a stereo pair, combines and attenuates those as needed, and then hands that off to a mono amp and center channel.

Erik

[Erik Mandaville]

Cod: I actually almost bid on that amp, but just wanted to build one for myself too much. On the headphone jack thing: The shorting jack has connections for either a shorting option is so desired, or not. I got some excessive noise through the speakers that way (while in headphone mode), and so I set the amp up to be able to switch between headphone out and loudspeaker out with the headphone jack still insterted into the female connection on the chassis. That's the only difference, really.

Craig Uthus has also designed a very headphone-dedicated version of the amp, which uses an isolated power supply in a separate chassis.

Smoke from the power supply?! Not good, and is a sign that something was amiss there.

Erik

[codhead]

[Erik Mandaville]

Absolutely. It's a wonderful two channel amplifier, and sounded great with our Klipschorns. It was a disappointment to me that it didn't work as well when combined with the Lexicon, but the digital 3-channel Teac we're now using for the front 3 speakers is doing a very nice job. But, I listen to the Moth every night with headphones during the week, so it actually gets significantly more use than the rest of the system -- which is on all weekend.

There had been quite a bit of an 'us and them' sort of attitude regarding the whole SET/PP (or rather high and low power issue), and I just think it's nonsense to argue about it. We should use what sounds best to our very own ears, and for me both high and low power can have their place -- especially within a multi-channel system.

Erik

[Marvel]

I think the newer mid driver for the Heresy (HII) is not designed to have as low a freq. output. The K55 should coast on the Heresy with a 700Hz crossover. That could also contribute to the differences you heard between the two models.

Marvel

[codhead]

[codhead]

[3dzapper]

"I'm still waiting for the power cord arguments to start, so that I can have some fun!"

You just missed one last month. A real Donneybrook too! Needless to say, that thread was not just locked, it was zapped.

Rick

[codhead]

[pauln]

Cod, others may confirm but I believe that one of the most contributing mechanical differences between the Heresey types I and II mentioned by Tom is the diameter of the diaphram in the mid driver - in the origina Heresey it is 2 inches like the rest of the Heritage. In the Heresey II it is only 1.5 inch.

Pauln

[codhead]

[3dzapper]

I see a little Photoshop action there. Looks good!

rick