Dec 302016
 

I’ve got today off from work so I’m playing hi-fi games with my Altec A5 Voice of the Theatre project loudspeakers, and I have a ton of fun things to tell you about!

Facebook also informed me that today is my one-year anniversary of starting my Altec A5 Voice of the Theatre project, and guess what, it’s (almost) finally done!

Woo hoo!

Vintage Altec Lansing A5 Voice of the Theatre loudspeakers.

First of all, the photo above is now out of date, as I started my morning by moving my mighty A5’s into my ‘home theatre room’. When I say ‘home theatre room’ it’s in jest as I’m about the least credible home theater guy of anyone I know.

In reality my ‘home theatre room’ is my smallish ‘guest’ bedroom that has an aging Philips television hung up on the wall so I can watch on occasional movie or TV show.

It’s a small space with the dimensions of 11-feet x 12-feet x 9-feet (ceiling), with a 6′ x 3’5″ x 9′ foyer on one end.

Secret #1: Altec A5’s & A7’s work fantastic in smaller rooms. Who would have thought? It’s a myth that Altec’s have to be used in large rooms, so if you have a small room and you want to experience that vintage Altec magic, you’re in luck.

My Altec A5 Voice of the Theatre project loudspeakers in their new home, the ‘theatre’ room.

In fact my guest room is such a small space that I couldn’t fit my jumbo-sized breadboard crossovers in the room with the speakers and the rest of the gear at the same time. What to do?

Fortunately for me, Pete Riggle volunteered to reconfigure my A5’s crossovers to a smaller footprint so I could place them on top of my 825B bass horn cabinets, so they would be out of the way, but still accessible so I could fiddle around with them some more as the mood strikes me.

Pete’s compact crossover layout for my Altec A5’s.

In order to keep things accessible and compact, Pete split the crossover board in two, with the high-frequency crossover section mounted on one board, and the low-frequency crossover section mounted on another.

The high-frequency section of the crossover board.

The low-frequency section of the Altec A5 crossover.

It’s kind of hard to tell from the photos, but my crossovers are an adaptation of Jean Hiraga’s superb 16-Ohm crossover design for the Altec A5’s, but with a few modifications in order to tame the 1005B high-frequency horns I’m using instead of the 3dB less sensitive 1505B horns that Hiraga-san used.

It’s kind of hard to see it in the photos above, but underneath the crossovers and the 1005B horn supports I’m using some exotic vibration damping material from The Soundcoat Company that I wrote about way back in November 2013 and January 2014, called Soundfoam.

The Soundcoat Company’s ‘Soundfoam’.

Soundfoam can be used anywhere isolation is required, preventing vibration from passing from one surface to another, and it works perfect to isolate my crossover boards and 1005B horn supports from the top of my 825B bass horn cabinets.

I’ll go into the details of the crossovers in a future post, as they’re still in a bit of a state of flux.

After I got the A5’s moved into my TV room I positioned the crossovers on the top of the 825B bass horn cabinets, then wired everything up.

Speaking of wire, for speaker cables I’m using single runs of Duelund DCA16GA tinned-copper wire, and in the crossovers I repurposed the Western Electric WE16GA tinned-copper wire used in the breadboard crossovers for use in Pete’s compact crossovers.

The Altec 515B bass drivers and Altec 288C compression drivers are wired with Western Electric WE16GA, as before.

Oppo BDP-83 Blu-Ray player show with Leben CS600 integrated amplifier.

I’ve been using my now older Oppo BDP-83 Blu-Ray player for watching movies on DVD and Blu-Ray, along with my trusty Leben CS600 integrated amplifier to provide the juice.

My plan is to move my Harbeth Super HL5 loudspeakers and Leben CS600 into my bedroom to create a system there, and by doing so I will have approached the goal of being more like Ron and having a hi-fi rig in every room of the house! 🙂

But for now I just wanted to make sure everything was working correctly so I hooked up the Leben CS600 to the Altec A5’s and let ‘er rip!

Good news on that front, as everything was wired correctly and working fine, and I started getting the high-frequencies dialed in better via the notch filter control and L-pad.

For interconnects I’ve got a set of Belden 8402 microphone cable interconnects from the Philips to the Leben CS600 for when I’m watching movies, and I’ve got a pair of the Duelund DCA16GA interconnects going from the Oppo BDP-83 to the Leben for listening to CD’s.

Secret #2: Digital sounds better than it has any right to with Altec’s, as I found before with my Stokowski A7 Voice of the Theatre loudspeakers, and now with my Altec A5 Voice of the Theatre loudspeakers.

Sablon Audio Quantum Gran Corona power cable.

I have been using the stock power cord on the Oppo, but in a wild hare moment I put one of Mark Coles’ Sablon Audio Gran Corona power cords on it, and it was completely transformed to a level a level of musicality & sonics that I never thought it was capable of. Just wow!

I’m having a ball going through my old CD collection this afternoon, which I’ve hardly listened to for years, and I’m amazed at how good CD’s sound on the Altec’s and transformed Oppo.

My next step is to finish moving my Harbeth / Leben system into my bedroom, as I’ve been wanting a system in there forever.

I’m not quite sure yet, but either my vintage McIntosh MC240 stereo amplifier or MC225 stereo amplifier will go into this system, along with one of my Leben line stages.

Leben RS100 line stage and vintage McIntosh MC240 stereo amplifier.

Update: I couldn’t stand waiting until later so I got out my Leben RS100 line stage and vintage McIntosh MC24o stereo amplifier and put them in the system to see what would happen.

I used a spare Belden 8402 microphone cable interconnect to connect the Leben RS100 and MC240.

A5 Voice of the Theatre loudspeakers with Leben RS100 line stage and vintage McIntosh MC240 stereo amplifier.

Update # 2: I just put my vintage McIntosh MC225 in the system with the A5’s, and what a great match!

Vintage McIntosh MC225 stereo amplifier with the A5’s.

McIntosh MC225.

Vintage MC225 stereo amp, nude.

I’m really enjoying the combination, and am signing off now for a little more music listening.

There will be more fun & games to come, and as always, thanks for stopping by!

 Posted by at 1:08 pm

  28 Responses to “Foolin’ around with Altec A5 Voice of the Theatre loudspeakers on a Friday off!”

  1. So, where did you migrate the A7’s?

    • Howdy Josh!

      My A7’s haven’t moved, they’re still where they were in their original bedroom/office room. They work so well in there I think I’d be afraid to move them!

      The A5’s displaced my Harbeth/Leben system out of my guest bedroom / TV room, and the Harbeth/Leben system will migrate to the master bedroom for a bedroom system.

      All the best,

      Jeff

      • Okay got it… I think! 3 rooms with 3 systems plus the main Tannoy system. Currently I have the Flamencos in my the bedroom of my new place as nightstands but may need to bring them out to the living room until my pair of 604s are finished (month or two). For the bedroom I’d like to use the Flamenco’s for basic listening and things like NPR and BBC. If you have any ideas for a solid state bedroom integrated let me know. I might try to run an Apple Airport Express directly into the Altecs. With 100 dB sensitivity I bet it would work for playing news and lullabies.

        • That’s right, Josh, 4 systems total now. One can never have too many hi-fi rigs! 😉

          I think a pair of Flamencos as night stands might just be the ultimate foundation of a bedroom system! The SPEC solid-state amp is magnificent with my A7’s, and I’ll bet it’d be superb with your Flamenco’s as well. Or maybe an older Sugden in good shape? Let me know what you decide on for your Flamenco’s, it sounds like a fun time!

          Happy New Year!

          Cheers,

          Jeff

  2. Nice job, Jeff! Woo Hoo!!! Pete

  3. Hidey-ho Jeff: Just a note to tell you that you got the titles reversed on your photos of the low and high pass crossovers. Best, Pete

  4. Hi Jeff,

    What a great home theater system! Hopefully, you can implement one of Jim Smith’s recommendations to cover the Philips flat screeen TV with a sound dampening material like a beach towel or some other textile when you just want to hear tunes. With the screen at the same height as the horns, you might get some undesirable reflections of the mids and highs.

    The Hiraga-san based crossovers look great on their new chasses and with all those vintage paper-in-oil caps. For improved vibration isolation, you might want to try a combination of 2″ x 2″ cut squares of The Soundcoat Company’s Sound foam with either E.V.A. anti-vibration pads or the similar rubber/cork anti-vibration pads (http://www.supplyhouse.com/Pads-11752000). I use 2″ x 2″ E.V.A. and rubber/cork pads under all my components, and they have worked very well. There are some audio accessories dealers who sell these same pads for a lot more money, but the best source for these are the HVAC equipment dealers who recommend these for vibration isolation for noisey HVAC equipment.

    I would think that the Leben and Mac tube amp combination is a highly musical amplication system. I would try your Playstation 1 game console with this system for CD playback as well. Those rubber/cork vibration pads work very well under the Playstation 1 chassis for vibration damping and for allowing better ventilation under the power supply so the Playstation can stay cool.

    Rich

    • Thanks, Rich, appreciated. It has been fun!

      My buddy George stopped by yesterday and we had a nice time listening to all the different systems here.

      George was impressed with how musical the Altec A5’s (and A7’s) were with digital sources, and I would agree, there’s something about Altec’s that makes digital sound better than it has any right to.

      Happy New Year!

      Jeff

  5. I do enjoy your blog and dream of an A7 or A5 based system but am not likely to go there Have you considered a low watt system, maybe full range driver system sort of a less is more bang for the buck system for one of your systems for experiments ? it would be interesting reading I have a low watt system and am very happy with it, Thanks, Darrell

    • Hi Darrell,

      Thanks for the kind words, appreciated.

      A vintage Altec A5 system can get kind of spendy these days because there are fewer & fewer of them coming up for sale, it seems. However, a vintage A7 in decent condition can still be bought for less than $2K, which I think is a bargain considering the extraordinary performance they are capable of. In fact a pair of fully restored A7’s can be bought for around $3K, which is still a bargain considering the level of performance.

      In the past I’ve actually had a bunch of low watt systems using various SET’s utilizing 45, 2A3, 300B, 845, etc., amplifiers, so you might want to take a look at some of my past articles to read some more about that.

      I like the low watt SET & SEP amps, they do some things very well, and in the right system context they can excel. These days I haven’t done much with SET’s and such, but I’m always open to checking out something new and interesting if it comes along.

      Best,

      Jeff

      • Thanks for your reply, I’m reading some of your reviews. I have put together a Decware se84ufo2 and Decware zp3 phono pre amp and music hall 7.1 with 6.5″ Fostex drivers in a BIB enclosure. I finally bought new gear, that I am happy with because no one could fix the old stuff so that it was dependable…..You need good friends with talent as my Dynaco sc35 that is in the closet is witness to. Looking forward to making speaker wires and getting some of the interconnects you recommend. Thanks, Darrell

        • Hi Darrell,

          Sounds like you’ve put together a nice system!

          It does help to have friends that know how to keep the old stuff alive, that’s for sure. I sure have been learning a lot from my friends on that front lately, and it has been a blast! Get’s kind of addictive!

          Let me know how things work out.

          Kind regards,

          Jeff

  6. Jeff, wishing you a super 2017.

    I have a David Berning 10 watt class A zero feedback amp using the 6b4 triodes.

    I was wondering if the Tannoy Canterbury would be a good bet with it. Or is 10 watts too little? I saw on the net there are a few who seem to be using Wavac 300 SET amp with their Canterbury.

    • Hi Premnath,

      If you only play music at low volumes you’ll probably be ok with around 9-10 watts. I’ve found with my Westminster’s that they do better with more power though, and to really get realistic musical performances about 25-30 watts is the minimum.

      Tell me how it works out!

      Kind regards,

      Jeff

      • Thanks Jeff. Something like the Altec A5 would be fine with 10 watts?

        • Hi Premnath,

          The Altec A5 or A7 will perform very nicely with 10 watts, although I confess I like them very well more powerful amplifiers as well, like my 25 watt vintage McIntosh MC225. 🙂

          Kind regards,

          Jeff

          • Hi Jeff

            Thanks. I am in touch with Gary Fischer for a pair of Altec A5

            Is there anybody you know who can build a good crossover network for these speakers. I have no DIY skills

          • Hi Premnath,

            Crossovers make or break the Altec A5’s, and the Hiraga-san crossover design is a great choice to get the most out of you A5’s.

            1005 and 1505 horns are getting scarcer and much more expensive for use on A5’s, and I would recommend that you consider Markus Klug’s wood horns that are reproductions of the 1005 or 1505 and reported sound better. If I could afford it, I would buy a pair of Markus’ horns right now to replace my 1005’s, but if you are starting from scratch, I’d go with them from the start.

            Pete Riggle has been making a few Altec crossovers for people, but he’s so busy with other stuff I don’t know if he would be available to do that or not, but I’d ask him to see if he’ll make a pair for you.

            I hope that helps!

            Kind regards,

            Jeff

  7. Happy 2017 Jeff,

    I recently bought a Mcintosh MC-225 following your recommandation. A sweet amp exactly as you said, different sounding flavor compared to my Shindo CC80 but as gorgeous. I am the second or third owner of this MC-225 since restoration done by specialists a couple of years ago. Good match with my Altec A7 (crossover not yet upgraded).

    The amp stay warm in the first two hours of operation, but the main transformer became very hot after four hours of continuous listening. I measured around 110 Fahrenheit (42 Celsius) on the main transformer. Tubes run rather cool in comparison. I measure -21.2 volts on output tubes.

    Did you experiment such rising temperature on the main transformer of your MC-225 after long listening periods?

    I have no idea what could be a normal temperature operation and if the precious transformers of this gem could degrade prematurely by the condition I experimented.

    Thank you for listening.

    Redj

    • Hi Rejean,

      I haven’t really checked the temp of my MC225 after long listening sessions, but I turned it on right after I got home from the office a few minutes ago, and I’ll check the temp after it’s on for around 4 hours and let you know what temp I measure.

      More to come.

      Update: Ok, after about 3 hours mine measures 104F, so I don’t think the temp you’re seeing after extended listening is anything to be concerned about.

      Kind regards,

      Jeff

  8. Hi Jeff. I am really enjoying your blog and love to check it out everyday. Right now i have a plan to build the Jean Hiraga crossovers for my a5. Can you help me about that crossovers like what crossovers point, is it second order?
    Thanks you very much and i am really appreciate

    • Thanks for the kind words, Kevin, appreciated!

      I don’t know the answer to your question about 2nd order, but I can tell you building up a pair of Hiraga-style crossovers for your A5’s will work very well.

      For specifics I recommend contacting Pete Riggle who has a very good understanding of these crossovers, and I’m sure he’d be please to offer you any insights that you might need.

      Best,

      Jeff

  9. Hi Jeff
    I’m debating over crossover designs for my 288 based speakers and noticed you had a well known autotransformer based unit before moving to the Hiraga based design.
    I would appreciate your opinion on differences you found between the two?
    Thank you

    • Hi Chris,

      The autoformer based crossover I tried was ok, but my experience is that I was able do a lot better by building a Hiraga-inspired crossover from scratch and voicing it specifically to my Altec A5’s and my personal tastes.

      A Hiraga-inspired crossover is a really nice design for Altec’s, and provides a really a captivating blend of musicality and sonics that I didn’t hear from the autoformer crossovers I bought for my A5’s.

      The Hiraga crossover was designed very specifically for Hiraga-san’s A5’s, so it needs a bit a tailoring & voicing to be optimized for combinations of Altec components that differ from Hiraga-san’s, or to align with one’s personal tastes.

      When Altec designed their crossovers they included adjustability for the HF, so their customers could optimize it to the various horns’ sensitivity that they offered.

      While I use the same drivers in my A5’s as Hiraga-san used, my 1005B horns are 3dB more sensitive than the 1505B horns that Hiraga-san used, so my crossovers HF needed to be attenuated to accomodate that, which is most easily done with an L-pad.

      Also, with the Hiraga-inspired crossover I as able to select specific capacitors & resistors to voice it exactly the way I like it, which is really valuable.

      So to briefly compare the two crossovers musically and sonically, when I finished with voicing my Hiraga-inspired crossovers, I ended up with A5’s that sounded smoother, more tonally rich, more timbrally correct, and more “real” sounding musically, as well as being more emotionally stimulating, than the autoformer crossovers.

      The autoformer crossover HF sounded edgier, harsher, less natural, not very “real” to my ears, and I never got the same level of emotional connection to the music with them that I did with the Hiraga-style crossovers.

      While the autoformer crossovers were a lot better than my stock Altec crossovers, they didn’t even come close to my Hiraga-inspired crossovers after I was finished voicing them.

      Pete Riggle has demonstrated to me how adaptable the Hiraga-inspired crossover is for various Altec loudspeakers, like my A5’s (16 Ohm) and Pete’s A7’s (8 Ohm), with the key being adjustability (an L-pad and a couple of optional HF circuit settings), along with a carefully selected combination of capacitors, inductors, and resistors to get it voiced in the desired way.

      For the upcoming Duelund crossover project for my A7’s (16 Ohm), I’ll stick to with the Hiraga-style circuit, with the exception of adding an L-pad to optimize the HF balance. I’ll be chronicling every step in the project here at my blog, with a feature article being written for Positive Feedback about the project.

      Pete Riggle is also working on a crossover design for Altec’s with 800Hz horns, like the Valencia’s, Flamenco’s, Corona’s, etc., that are based on the Hiraga design, which I’m really looking forward to hearing more about from Pete, and which I’ll be chronicling here at my blog, and will be writing a full article about for Positive Feedback.

      Stay tuned, I’ve have lots of interesting Hiraga-style crossover discussions and projects to write up over the next 6 months or so!

      Kind regards,

      Jeff

      • Thank you for your in-depth response Jeff!

        There is so much conflicting information regarding the Hiraga xover out there- I really appreciate that you took the time to answer my question so comprehensively. I think that’s enough to sway me to the Hiraga.

        Time to begin sourcing parts.

        Cheers
        Chris

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