Parts Express 1" Horns and Waveguide Buy Out Specials

July was a hectic month - four 4th of July concerts with Harrisburg Symphony + two concerts at the Shippensburg Summer Music Festival. It was a welcome respite to receive an invitation from Joe Roberts to meet him at his mom's house in South Philly after I was done with all those gigs.

Leica II + Summitar 50mm f2
Ilford FP4+ in Kodak HC110

He gave me a tour of his old neighborhood, pointing out areas where he started his archeological expeditions as a kid. For lunch we stopped by this hoagie shop for really great Philly cheesesteaks. 

It was very interesting to listen to his recollection of South Philly as a kid, and how the area continues to evolve as people of different ethnicities, socio-economic and cultural backgrounds come and go.  

Before I-95 swarmed with rush hour traffic, I had to head back north with this box filled with horns from Joe. I didn't envision writing about 1" format horns again since I posted this blog entry last February. But after spotting the Azzolina KS12024s, it was hard to pass up this opportunity. Meanwhile, this post will focus only on the Parts Express horns.

Testing

I used Altec 802 1" compression drivers fitted with GPA 34852 16 ohm diaphragms mounted on top of Altec 614 cabinets loaded with 414A woofers (running full range) with the crossover below tying things together. All listening was done in stereo in the man cave.

High pass @ ~ 2500 Hz

I used these two horns as references and for the first time I was able to convince my wife, Tish, to indulge me with her sonic impressions.

Altec 32C

Tish and I love this descendant of the old school WE32A horn. She describes it as sublime.😉 

Emilar EH500

This is my favorite horn from the 70s. It was designed by Jonas Renkus who worked with John Hilliard at Altec Lansing. 

Parts Express Specials 

Round 1 

(deeper/longer exit Altec 802)

Parts Express: 299-2303

+

Altec 802

There is an ongoing thread at Hi-Fi Haven about cheap horns where this particular horn/waveguide was mentioned. Its specs are listed as a 600 Hz, 10" x 14" exponential horn waveguide with a 90° H x 40° H dispersion pattern, made out of heavy ABS plastic. Price: $12.88/ea.

Sound

Tish: Not bad, but not as lush sounding as the Altec 32C. It will eventually hurt my ears. 

JE: Tonal balance is reminiscent of the Emilar EH500. However the sound gets congested with complex musical passages (especially at higher SPLs) which can cause fatigue during long-term listening.

Community UC-1
part# 299-522
+
Altec 802

Dimensions: 10 3/8" W x 5 7/8" H x 6" D

Dispersion: 90°H x 40°V

Cut off frequency: 2000 Hz

Price: $4.48/each

 I had to DIY adapter plates to mount the 802 drivers.

Sound

Tish: Harsh and shouty👎👎👎

JE: Sounds better disconnected. What were you thinking J-Rob???🤣

Faital Pro revisited

Faital Pro STH100 + Altec 802

Dispersion: 80° H x 70° V

Dimensions: 7" W x 4 3/4" H x 3 5/8" D

Material: Metal

Price: $67/each!!!

Sound

Tish: I like this best among the three - easier on the ears compared to the other two, but not even close to the 32C.

JE: I am less impressed this time around despite the clean sound. It has less congestion, harshness and tizz than the B52/QSC clone 299-2303. But the presentation still falls far short of what I hear live. With the recent price increase, I can no longer recommend this unit.

!!!STOP PRESS!!!

Pasted below is a post by @ARX in this Hi-Fi Haven thread

Gentlemen,

Very interesting experiments with different types of horns and waveguides (the B-52 1" QSC clone is a waveguide), both vintage and more recent designs.

The 802D with the B-52 1" might not be an optimal combination. The original QSC PL-000446GP was designed by Mark Engebretson, former VP of Engineering at QSC, to be used with Celestion compression drivers. From the many measurements available online it's obvious this waveguide performs best with modern, pancake style compression drivers, that have a short exit instead of the deeper/longer exit of most vintage drivers like Emilar, Altec etc.

You might try B&C, Celestion, Beyma, BMS and similar 1" drivers.

There's much more to the underlying physics, but it should come as no surprise the EH-500 and Altec 32A/B do indeed sound wonderful with the vintage drivers. The gradual expansion of the wavefront from driver diaphragm to horn mouth is (almost) perfect. On the other hand, a pancake driver behind an oldskool horn, with a few exceptions, is unlikely to yield spectacular results.

Altec 802 (left) + Renkus-Heinz SSD1400-8 (right) 

The only pancake type (short/fast exit) 1" compression driver I have on hand is a pair of Renkus-Heinz SSD1400-8. This is a smaller magnet version of the SSD1800, which I got to know quite well in the attic. Hence, I had a gut feel that I was going to learn something important from @ARX. So the SSD1400-8 was pressed into service for another round of listening.

Round 2 

(short/fast exit Renkus-Heinz SSD1400-8)

Parts Express: 299-2303

+

Renkus-Heinz SSD1400-8

 According to ARX's post above, this is a clone of the QSC waveguide, which was designed to be paired with a B&C DE250 compression driver in the Econo-wave project at Audiokarma.

With the short exit R-H SSD1400-8 mounted, this waveguide was transformed. Although not quite on the same level, the sound now more closely resembles the Altec 802/Emilar EH500 pairing. The congestion I heard in Round 1 is gone with a substantial gain in midrange lucidity. Long term listening fatigue is no longer an issue since the sound has opened up with a nice airiness to it.  👍👍👍

Community UC-1

part# 299-522

+

Renkus-Heinz SSD1400-8

This horn became a lot more listenable with the SSD1400-8 mounted behind it. It sounded even better crossed over @ 5kHz. Detailed and airy but the midrange isn't quite as vivid as the B52/QSC clone/299-2303. For the record, Community compression drivers are also short/fast exit (pancake) designs.

Faital Pro STH100 

+

Renkus-Heinz SSD1400-8

Sadly, this tractrix horn became unlistenable with the SSD1400-8. Probably a mis-match? Faital Pro 1" compression drivers look more like old school Altec 802s and Emilar EA/EC175.

Parts Express Horn Wrap

Two important lessons learned:

1. Thank you very much @ARX for enlightening me! Otherwise, I would have joined the ranks of fake news bloggers. 🤣

2. My preference for matching harmonically rich-sounding components will always entail a classic pairing of units that are long out of production and are becoming more unaffordable as the years go by...😞

Raspberry Pi 3B+

The FM tuner has been a de rigeur music source in my audio system. Between the dwindling quality of FM broadcasts and proliferation of internet radio and music streaming apps like Pandora, Spotify, Tidal etc., I had to jump the bandwagon with my first generation iPad mini.

But as I delved into how to get the best sound from the internet, I realized that I could improve upon the iPad mini > USB DAC set up for not much $$s.  I've seen Blogs and YouTube videos on how the Raspberry Pi 3B+ (henceforth, RPi3B+), a 40 something dollar single board computer, can be configured as a hi-fi music player.

 A discussion of the RPi3B+'s sonic merits in the Joe-list initiated by a long-time audio DIYer, Larry Moore, was pivotal in my decision to try it. He recommended using the RPi3B+ with an I2S Allo Boss DAC, moOde 4.1 + a linear power supply. Since I already had a couple of USB DACs, I just opted for the cheapest RPi3B+ bundle with a 5V/2.5A SMPS (switched-mode power supply), a molded transparent acrylic case and a couple of 16GB micro SD cards from Amazon.

The software for the RPi3B+ is contained in a micro SD card, which is inserted in the bottom mounted front slot. At the back is an ethernet port + 4 USB ports which can be loaded with USB thumb drives filled with music files and/or connected to an outboard DAC. On the right side, there's a mini USB for 5V power, an HDMI port and a 3.5mm below hi-fi grade audio out. 😞 To the left is a 40 pin GPIO header where an I2S S/PDIF device or DAC can be attached, which supposedly offers even better sound due to less jitter.  

 Once the software is loaded and configured the RPi3B+ will be operating "headless" (no monitor or touch screen). All functions are accessed and operated via a web browser on an iOS/Android device or laptop.

moOde 4.1

moOde GUI

Installing moOde 4.1 was not an easy task - not for me, at least. I had to bring the TV near the router to function as an HDMI monitor and plug a USB keyboard on the RPi3B+ to type commands which reminded me of WordStar word processing on an IBM XT/AT in the 80s. After two trials using the EZ install process and valuable assistance from the good guys at Hi-Fi Haven, my moOde 4.1 build was a success. 

The only glitch I had with moOde 4.1 is that Airplay doesn't work with the following DACs via USB: AQ Dragonfly Black, XtremPro X1 and Topping D30. So far I can only get moOde 4.1 Airplay to work with the Xiang Sheng DAC 01A below. I'm hoping that an update will address this issue. 

Volumio

Volumio GUI

After the moOde 4.1 initiation, installing Volumio was a breeze. The software is downloaded as a file, "etched" on a 16GB micro SD card and then set up for Wi-Fi connection. No MS-DOS style typing required. Everything went smoothly even for a not-too-tech-savvy computer user like me. There were no issues with Airplay connection, regardless of which DAC was connected to the USB port. The choice of internet FM radio stations is at par with moOde 4.1 and there's a "plug-in" for YouTube. There's also support for Spotify subscribers. Since I only have a Spotify free membership, I "Airplay" from an iPad.

Sound

I wouldn't have known that the software itself can influence the sound in computer audio if I didn't embark on a Raspberry Pi journey. The more complicated set up procedure and USB > DAC issues notwithstanding, moOde 4.1 rewards the listener with deeper and punchier low frequencies, crisper high frequencies and more lucid midrange. Volumio sounds as if the leading edge of transients are slightly rounded off. The difference is actually quite subtle and only discernible after extended listening to both platforms.

According to MikeyFresh, a moderator at HiFi Haven who helped me a lot with the moOde install, "Moode is a very lean distribution, perhaps that's why it can sound better, it runs super efficiently and thus taxes the RPi3's CPU and RAM very little, which in turn produces less EMI/RFI to contaminate the signal." 

iPad mini as controller, RPi3B+ and Topping D30 DAC

I'd hate to bid adios to my beloved Scott LT110B and Dyna FM-3 tube tuners, but the RPi 3B+ is getting more air time nowadays. 

!!!STOP PRESS!!!

I initially considered the cheaper Hifiberry Digi+ Pro, but based on the positive reports I've read on the internet from RPi users, I took the plunge and got the more expensive Allo Digione S/PDIF HAT (aka Hardware Attached on Top) instead. A layer of electronic hash was removed by this I2S device and took the sound quality to another level = more analog, less digital. 

Lafayette SK98 Reunion

 
Many years ago, I wrote about vintage Japanese drivers. From that survey, the 8" Lafayette SK98 aka Pioneer PIM8L full range driver emerged as a favorite due to its vivid midrange, balanced by respectable high and low frequency extension. Thinking that I could easily find replacements, I eventually unloaded both pairs to friends who didn't have the budget for Altec 755As. 

Lafayette SK98s in Altec 618 clones

Over 10 years have elapsed and I am happily reunited with a pair of SK98s, courtesy of my friend at Junkyard Jukebox. He believed that his treasured pair in Altec 618 clone cabinets should be in the JE Labs collection.

 Welcome back old buddy and thanks J-Rob!

Ortofon SPU #1S and the Enigmatic Spherical Stylus

Garrard 301 + Ortofon RMG309 + SPU Classic GME

It seems like yesterday when my SETUP friends Joel, Nonong and William gifted me with an Ortofon SPU Classic GME cartridge for helping them get rid of the upgrade syndrome afflicting their high-end audio sensibilities back in the mid 90s. Within the same time frame, I was frequently talking shop with Sound Practices editor and publisher, Joe Roberts, regarding my Homebrewer article. At some point, the conversation segued to the virtues of the spherical or conical stylus based on the research done by Reto Luigi Andreoli (published in German by Christian Rintelen in Hi-Fi Scene Schweiz). Looking back, and at the risk of sounding ungrateful to my friends, would the humbler Classic GM have been a more appropriate gift? 😇

In the process of hunting for an original SPU with conical stylus, I instead landed three Denon classics - a ca. late 80s DL103, DL103S and DL103C1- for the price of a then brand new DL103R. Compared to a regular DL103, the DL103S is sweet and most extended in the high frequencies but least dynamic, the DL103R most detailed. The DL103C1 emerged as my favorite for combining all the virtues of the aforementioned models. These are very competent MC cartridges, which, along with the SPU GME, have been invaluable tools in voicing my audio system through the years. However, none of them could match the vivid midrange presence of the SPU.

Meanwhile, my spherical SPU hunting got sidetracked by Monaural playback and Retro Cool Tonearms and Cartridges.

Ortofon SPU Classic GME

In the intervening years, I had been fortunate to listen to higher-end Ortofon SPU models in familiar systems. Inasmuch as the SPU Royal, 85th Anniversary, Meister and Synergy offered better detail retrieval and extension in the frequency extremes to satisfy contemporary audiophile standards, I was never convinced that they were presenting a tonally more accurate sound overall.

Ortofon SPU#1S

After over 20 years, the idea of owning a spherical stylus-equipped SPU still haunted me. Fortunately, Ortofon introduced two entry level SPUs in 2016. I bit the bullet and ordered the cheaper SPU#1S with a bonded spherical stylus last year and couldn't be happier. Even if the #1S has slightly less top end extension than the Classic GME, the midrange is even more organic and soulful because the harmonic overtones are more akin to what I hear in a live music-making environment.

It's been known for decades that a conical/spherical stylus is kinder/gentler to the grooves. Thus records in less than perfect condition become more listenable traced by this type of stylus. Granted its technical inadequacies can be measured, which in turn has pre-conditioned audiophile beliefs for several generations, what matters most to me is still the enjoyment of music, and a measuring tool for that has yet to be invented.

While perusing various audio forums these past couple of years, I noticed that compared to 20 years ago there are a lot more vinyl aficionados who recognize and appreciate the musical merits of the humble round profile stylus. In hindsight, if the Retro Cool Tonearms and Cartridges article I wrote before my hair turned gray contributed to this trend, my efforts have not been in vain.

Velvet Touch, Calrad SV12 + SV16

I may have shot myself in the foot when I spilled the beans in the original Retro Cool Tonearms article many moons ago, before collecting all the desirable models of viscous damped tonearms. 

But it's all good - more good karma to come, hopefully. 😇

I no longer aspire to be as lucky as my buddy Ding with his Gray 108 and Gates CB77. 😞 But I recently found a transcription length Gray clone locally, a Calrad SV16 complete with original box and instructions. 

Calrad SV16
Pivot > spindle = 276mm

Neat P58H + SV16 + GE RPX 

Top: Calrad SV16
Bottom: Velvet Touch (aka, Calrad SV12)

Courtesy of Ben C

Here we have the instruction manual for the Calrad SV12 which is also applicable to the Velvet Touch.

Neat P58H + Velvet Touch (aka SV12) + GE RPX

Velvet Touch or Calrad SV12
Pivot > spindle = 8 3/8"

Musicmaster Model 12 installed as per the above 8 3/8" pivot to spindle distance. Sounds okay. But read further...

This is my Realistic Mk VII idler turntable with a factory mounted Realistic A-3 viscous damped tonearm, which is identical to the Calrad SV12 and Velvet Touch.

 Pivot to spindle distance = 220 mm or 8.66142" or between 8 5/8" and 8 11/16".  

This is my preferred setting after listening to the following cartridges: Denon DL102, GE RPX and VRII + low cu stereo cartridges like the PickeringV15/Stanton 500, Shure M7D & SC35C.

Neat P58H + Calrad SV16

I've also gotten good feedback from ears I trust regarding brand new Gray 108 clones from Karmadon. Serge has come up with variations on the viscous damped tonearm theme. This route is well worth pursuing since prices on eBay for the original 108 and clones have become ridiculous.

Happy Listening!