Now, I have the Mods Completed on My 1Cs!

Moose68Bash

1.Installed RDO 194 Tweeters

2.Installed Crossovers Upgraded by Vr3 Mods:
a. Gimpod Boards
b. Clarity Caps

i.Tweeter Network: Clarity Cap ESAs:
ii.Midbass Network: Clarity Cap PXs

c. Mundorf Resistors
d. Jantzen Perfect-lay Inductors: Board-mounted & SDA

3.Custom SDA Interconnect Cables by Vr3 Mods:
a. Supra Rondo 2.5 Cable
b.Neutrik speakOn NL2FC Male Connectors (Speaker Ends)
c.Banana Connectors (Dreadnought Ends)

4.Custom Aluminum Binding-Post Plates by Vr3 Mods:
a.Upgraded Binding Posts
b.Neutrik speakOn NLJ2MD Female Jack Receptacles for SDA Cables

5.Dreadnought SDA Amplifier Interface per DarqueKnight’s Design:
a.Toroid Corporation of Maryland 600VA Transformer
b.“Larry’s Enclosure” by Toolfan66
c.Cardas CCGR Binding Posts

6.“Larry’s Brackets & Rings” by Toolfan66:
a.Brackets for Tweeters
b.Rings for MWs and PRs

7.Black Hole 5 Installed behind Tweeters, MWs, and on Sides in Cabinets

8.Dynamat Xtreme on MW and Passive Radiator Baskets

9.JB Weld on MW Magnets

10.Custom-cut Gaskets for PRs (1/4” Neoprene Material)

11.Spikes

First impressions of sonic performance:
Immensely improved clarity, definition and openness of the high frequencies -- e.g., in Rebecca Pidgeon's rendition of "Spanish Harlem" on Chesky's "The Raven" CD.

Greater depth and clarity and power in the bass. Timbre of the instruments came through clearly and accurately -- e.g., bass violin in the Turtle Island String Quartet, "Windham Hill Retrospective."

Overall, the accuracy and richness of the sound reproduction is remarkable even at this early stage of burn in, and I'm sure it will get better and better.

Well done, Trey! Thank you, once again for all your good work, help, and advice.

Thanks also to DarqueKnight, Toolfan66, F1Nut, drumminman, nspindel and everybody else on the Forum who have searched for, found and passed on information about these mods that have made it possible for a neophyte like me to get this done -- one way or another.

Here are some pictures of the process:

nspindel

Outstanding! So you are using a Jantzen for the 16mH inductor. Sweet. One question, what happened to the 1000VA isolation transformer you bought?

Moose68Bash

nspindel wrote: »

Outstanding! So you are using a Jantzen for the 16mH inductor. Sweet. One question, what happened to the 1000VA isolation transformer you bought?

It's being put to good use in the Dreadnought I built for my main system. See picture below:

Next time you organize a group purchase of the A-L 1000VA transformers, I'm in!

I'll use a new A-L 1000VA to replace the 600VA transformer in the Dreadnought I use with the 1Cs, which are not driven by a non-common ground amp and don't require the Dreadnought. However, I believe the Dreadnought definitely improves the sound -- at least, it did before I installed all these mods. I have not done a comparison with and without the Dreadnought since the mods have been in place.

Toolfan66

Very Nice Project!!

Glad I got to be part of it...

600VA?? are you sure it's not 800VA??

nspindel

Moose68Bash wrote: »

It's being put to good use in the Dreadnought I built for my main system...

Ah, so modded 1C's are not the main system. Nice to be you!!!!

Moose68Bash

Toolfan66 wrote: »

Very Nice Project!!

Glad I got to be part of it...

600VA?? are you sure it's not 800VA??

It's the TCM 767-1202 isolation transformer, and the correct spec is actually 670VA. I'm sorry that I got it wrong in the post. I put 600VA in from memory, and my memory is obviously not perfectly reliable -- although it is predictable. The older I get, the more often those predictable little mistakes pop up! :mad:

The managing engineer at Perreaux recommended that transformer when I first encountered the "non-common-ground" problem with the monoblocks I installed about a year ago.

He also introduced me to the Polk Forum and the Dreadnought, and my life has not been the same since! :biggrin:

Moose68Bash

nspindel wrote: »

Ah, so modded 1C's are not the main system. Nice to be you!!!!

I confess that I feel blessed to have mod'd SRS1.2s in my "main" system, and, now, mod'd 1Cs in my exercise area. Actually, I feel that I am being terribly self-indulgent.

Because of physical therapy that I have been doing for my back for over 20 years (to avoid back surgery), I spend around two hours per day, five days per week, in my exercise area, and I think I earn the modicum of self-indulgence my 1Cs give me.

I love it!

Toolfan66

My 1C's are not in my main system and I gave my CRS+'s to my son..

Moose68Bash

Toolfan66 wrote: »

My 1C's are not in my main system and I gave my CRS+'s to my son..

One of my motives in upgrading my 1Cs was, perhaps, to give them to my daughter for her condo (along with one of my vintage Perreaux preamp/amp combos). However, the "decorators" in my family have ruled that option out for the time being.

Unfortunately, my daughter's loss and my gain! :biggrin:

Oldfatdogs

Nice project Moose,im going to assume that's the high performance upgrade from Trey.I have looked on his site at the Gimpod standard upgrade,you seem to have a few extra parts from that one correct?

Moose68Bash

Oldfatdogs wrote: »

Nice project Moose,im going to assume that's the high performance upgrade from Trey.I have looked on his site at the Gimpod standard upgrade,you seem to have a few extra parts from that one correct?

It would be fair to say that I pretty much did what Trey advised me to do. When alternatives came up, I asked him about the relationship between cost and sonic benefit, and we went with the option Trey said yielded a sonic benefit that was worth the cost. We did the same thing with the SDA SRS1.2 crossover mods.

I really respect Trey's opinions and his interest in giving his customers good value for their money, and my experience with his work is that my confidence in his judgement is 100% justified.

PolkieMan

Good write up and pictures, very very nice.

george daniel

nice work indeed!

nspindel

You don't need me to organize a group buy. Why not try one yourself. Just put up a thread about it. If you get ten people, then go forward, if not then you're not out anything.

If you swap the 670VA vs. the 1000VA in and out of the same system, can you hear a difference?

TNHNDYMAN

Great job Moose! Those look really nice and I'm sure the upgrade will keep you happy for a long time.

StantonZ

Impressive; nice pics. I would be interested to know your PARTS cost (R/C/L--not the tweeters).

VR3

I love the lexan mount, turned out fantastic!

looking good Phil!

Moose68Bash

StantonZ wrote: »

Impressive; nice pics. I would be interested to know your PARTS cost (R/C/L--not the tweeters).

Thank you. I still haven't mastered the art of transferring pictures to the Forum threads, but I'm improving.

I'll try to dig through my records to find out what the parts costs were from Trey's quotes to me. I won't be able to get to it, perhaps, for a couple of days.

Mike Reeter

Man, Those are a very good lookin' pair of 1C's! I roll mine in/out of our rig quite often, they are a excellent speaker in their stock form, you have taken them beyond the next level.

I have the Sonic Cap/Mills combo in mine, I might have to give Trey a call and "get the works" :biggrin: n'joy

Moose68Bash

nspindel wrote: »

You don't need me to organize a group buy. Why not try one yourself. Just put up a thread about it. If you get ten people, then go forward, if not then you're not out anything.

If you swap the 670VA vs. the 1000VA in and out of the same system, can you hear a difference?

After I get the stuff done that I still have ahead of me -- building four power cords, modding some old Allison 6s -- I may try my hand at putting together a group buy of more A-L 1000VA transformers. I guess I'm too wrapped up in my current projects to launch another one right now.

When I swapped out the 670VA for the !000VA in my main system, both my wife and I heard immediate improvement, and we noticed it even more after several hours of "burn in." I think I posted some observations on one of the threads on the Forum at that time, but my recollection is that the effect was that the system just "blossomed." That isn't very descriptive, but the improvement was general -- that is, appreciable on virtually every dimension. Most important, my wife confirmed that it was a mod worth doing.

nspindel

That's a good woman you've got there.

Moose68Bash

nspindel wrote: »

That's a good woman you've got there.

I am truly blessed and undeserving!

Here's what I wrote about the 1000VA after we had listened to it for a few hours (this is all in comparison with our prior experience with the 670VA transformer):

"Well, we now have about 12 hours of listening time in, and this rig has truly blossomed!

"We're listening to Ray Charles's "Ray Charles: Genius Loves Company." It is magnificent! The sound stage is about six feet wider on both sides and very deep -- Ray and his piano are about three feet in front of the plane of the speaker fronts and the orchestra is arrayed across the entire soundstage behind him and the individuals with whom he sings successive duets.

"The instrumentals are deep and clear. The vocals are beautifully precise, clear and warm! The transients are fast and detailed. I don't know what more to say other than I hope things just keep getting better -- but I don't know where they can go from here. I'll just sit back and enjoy the ride. (Current duet is with Willie Nelson singing "It Was a Very Good Year," and Willie just sang the "when I was 35" segment!) Beautiful.

"Close my eyes and it sounds like they're all in the room with me.

"Trey, DarqueKnight, Toolfan66, nspindel, drumminman and all those who helped me along the way with these mods, a mighty big thanks!"

PolkieMan

Yep that's the SDA EFFECT there is no other like it! IMHO:biggrin:

Close my eyes and it sounds like they're all in the room with me

Moose68Bash

StantonZ wrote: »

Impressive; nice pics. I would be interested to know your PARTS cost (R/C/L--not the tweeters).

Here are the prices Trey quoted for the SDA 1C's parts:

Tweeter Network -Clarity Cap ESA, Mundorf Resistors
Midbass Network -Clarity Cap PX
SDA connection + upgraded binding post Speak On, 15 feet long, 13awg wire

Parts -
Caps/Resistors/SDA wire
$296.60 + $14.00 Shipping

The Jantzen Perfect Lay inductors were priced at an additional $298.00, including shipping.

Total (with shipping): $594.60

VR3

I wanted to comment that the inductors were that price because we purchased them from a UK source that does 2-3 week shipping vs 6 to 8...

And I actually stopped using them as shipping cost from them recently went to over $100.00 and that simply does not make any sense

Moose68Bash

As Shakespeare said, "The course of true love ne'er doth run smooth."

After my initial delight with the performance of my newly mod'd 1Cs, on Friday when I went to my exercise area for my daily physical therapy routine, I turned on my system and got on the arc trainer for an aerobic workout.

I realized quickly that the sound between the two channels was not balanced; there was very little sound from the left channel 1C speaker.

Here's what I did to try to identify the problem:

First, I checked all connections. They were secure.

Second, I adjusted the balance to see whether I could get more sound out of the left channel. The result was that the overall volume went down when I increased the signal to the left channel, but this did not increase the sound out of the left channel.

Third, I disconnected the SDA interface from each speaker to see whether the faint sound I was getting out of the left channel was the SDA signal through the Dreadnought. This action had no effect on the left channel sound. (I don't understand the SDA circuit well enough to know whether this "diagnostic" really made any sense.)

Fourth, I disconnected the 1Cs and connected my Allison 6s. Bingo, great sound again.

Then, I sent an email to Trey at Vr3 Mods describing the problem and what I had done to identify it. Over a period of a few hours and in several emails Trey suggested a number of things to do. As always, Trey showed that his first concern is solving problems, especially with folks who have had work done by Vr3 Mods.

Omitting several steps to make a long story short:

Trey thought there might be a problem with the stainless steel machine screws and washers that I used to mount the crossovers on Lexan plates. He tested his hypothesis with a spare GIMPOD board and a machine screw and discovered that in some instances current was passing into the screw from contact with the board.

He wrote to me:

"I actually was able to get the rod to keep a resistive load, simply lightly keeping it to one side of the board to keep contact and it maintained a 3.5 ohm load in the midbass circuit.

"On other parts of the board it was fluctuating between .5 ohms and 0. With this information I am hoping everything will be ok..."

He recommended that I unmount the crossover boards from the Lexan plates to see whether this solved the problem.

This morning, I removed the PRs, disconnected the new crossovers and SDA inductors and reconnected the stock crossovers and SDA inductors. The 1Cs performed properly, which indicated that the problem was with the left channel crossover/SDA assembly.

So, I unmounted the crossover boards from the Lexan plates, removed the stainless steel screws and washers from the GIMPOD boards, and reconnected the new crossovers and SDA inductors. Again, the 1Cs performed properly.

After a trip to Home Depot, I remounted the crossover boards on the Lexan with nylon machine screws, spacers, and washers. When I reconnected the crossovers, the 1Cs performed properly, both confirming that the problem had been with the use of conductive screws to mount the GIMPOD boards on the Lexan plates and solving the problem.

While this was an interesting exercise in problem solving for a newbie like me, it was undoubtedly a distraction for Trey, who nevertheless once again really showed his sincere concern for helping a fellow Polkie in trouble. He went above and beyond to give me advice and to follow up on my results.

I am posting this "story" for two reasons:

1) As further testimony to Trey and Vr3 Mods and
2) as a warning not to use conductive materials to mount GIMPOD boards in speaker cabinets.

The remounted crossover board on the Lexan plate, using nylon machine screws, spacers and washers.

Mike Reeter

Service AFTER the sale...priceless

Moose68Bash

Mike Reeter wrote: »

Service AFTER the sale...priceless

Amen!

Moose68Bash

Just to round out this story as I move on to mods on my old Allison 6s and completion of power cable builds:

As I expected, the more I use the 1Cs, the better the sound gets. While the setting for this system (an exercise area in my basement, which is a large open space with the kinds of detritus characteristic of basements! ) is far from ideal for evaluating a system's performance, I am confident in saying that the sound has improved dramatically after about 30 hours of use.

The highs are very crisp and clear, the transients in blue-grass music (e.g., Andy Carlson Band's "Fiddlehead" and Lenny Solomon's "Bowfire") are clear and precise, as they are in Bella Fleck's classical banjo renditions in "Perpetual Motion."

Midrange sound is distinct and mellow in a good sense -- e.g. vocals and instrumentals in David Johansen's "Shaker."

Bass is wonderful: Compact, punchy, nicely tactile, as in Mark O'Connor's Hot Swing Trio's "Live in New York," as well as in the above selections.

Because of the space in which this system performs, it is difficult to evaluate the soundstage, except 1) that in the "sweet spot" the rendition of the music is very realistic with respect to both the location of vocalists and instruments and the apparent movement of sound around the stage as parts change in the music and 2) that the power of the projection virtually fills this large space with sound, even at moderate volume levels.

All in all, these speakers produce great sound in a difficult context.

An aside: Just as I was reconnecting the 1Cs into this system, the on/off switch in my 25+ years old Perreaux PMF3150 amp failed; the switch would not remain in the "on" position. I had to replace it with my Perreaux PMF2350 (same vintage) while the 3150 is being repaired. When I have the more powerful 3150 (300 wpc into 8 ohms v. 200 wpc into 8 ohms) back in the system I expect to get even better performance.

Once again, thanks to all those on the Forum who made it possible for me to make these improvements in my system, and especially to Trey for his excellent work, great follow-up, and sound advice (pun intended ).

VR3

Awesome to hear! Keep rocking and rolling! :]

zane77

You and Trey did a magnificent job on those. I am just getting ready start getting all the parts together for my crossover mods so it was nice to see your step by step implementation.