Before I had speakers that had some good bottom end I played around with a powered sub.
I started out with a PAS3 and an ST-70, both refreshed to stock in by Joe Curcio (Dynaco Doctor). He lives within 1 hour driving distance; he’s a good fellow, took his time with me and really helped me get started.
I wanted to hear what they sounded like in their basic form. He did bypass tone controls in the PAS3, fixed the RIAA on the phono stage and he strongly suggested that I dump the 7199 tubes on my amp that were out of spec for the SA-6GH8A 9 PIN Socket adapter with some 6GH8A’s. His advice from the cost & sound standpoint did not steer me wrong.
I listened to that set up for a couple of years. Just running some homegrown speakers that I had laying around, even though they had been sweetened up with super tweeters & crossover upgrades, they were nothing special.
When I was leaving Joe’s shop one day, he knew what my setup was like, I asked him what speakers I should try to learn the sound of my gear, he pointed up to a pair of Dynaco A-25’s and said why don’t you try a pair of those… good advice.
Year later, looking for some more bottom end… I picked up a pair of Klipsch Hersey’s. Great speakers, super soundstage, imaging, still not hitting the bottom end I was looking for… even after I did the top of the line Critesspeakers.com crossover rebuilds… still not getting the big bottom sound I was looking for.
I then decided that I needed to add a subwoofer to the Hersey’s because I could not afford any other speakers with that sub 50 Hz frequency responses.
So I picked up an ENERGY EAC electronic crossover. But the PAS3 could not work with it connected up to the RCA jacks due to the impedance mismatch (that issue you will not have with your ZMOD boards by the way), so…
Back to Joe (Dynaco DR), he installed a tube Cathode Follower Mod into my PAS 3. Sha-zam, I could use the subwoofer that I have for the home theater system with the vintage tube stereo system, getting the bottom that I was looking for!
It was a huge success.
Luckily I fell into a pair of 1972 Bozak Symphony Speakers with the N-106B Active Bi-Amp Crossover network with the N-104 & N-107 crossovers and a pair of Bozak B-313’s. These were gifted to us from a wonderful family for a charitable donation to a charity of my choice! These speakers fill in the bottom end without any extra subwoofer or any other accouterments.
So I no longer use the EAC, Dynaco A-25’s or the spiffed up Klipsch Hersey’s, the old home grown speakers are in the shop used for testing… I still have the ENERGY EAC electronic crossover, it’s hanging around, waiting for the next system it could be used for, or for somebody who needs it.
I did the ZMOD mod to the PAS3, liked it, but decided I missed tone controls with the Bozak speakers, so I went with the TCLA setup. The ZMOD line board lives in a tricked out PAT-4 case. My ST-70 runs the VTA70 ‘classic’ driver board. My Symphonies are Bi-Amped using the Bozak N-106B crossed at 400Hz with a SS Carver A-220 running the 4 - 12" woofers.
At this time I’m playing around with DACs. I’m tuning up a Lampucera1.0 + Lampizator CS8416 + CS4397 kit, I can choose to use it with or without the tube stage, looks promising.
With a Red Baron V5 & Tube-I-zator V3.1 build on the horizon. There are pictures of all of this on my Google+ profile.