Hi everyone,
I just bought a pair of Acoustat model 3's with 121 interfaces, and I replaced the binding posts and did the c mod with all metallized polypropylene caps. My main listeners are magnepan mg III's and I was hoping to replace them with the acoustats since the acoustats are so sturdy, but I find the soundstage to be distant instead of in the room and the top end seems rolled off. Is there anyway to make them sound more up front and extend the top end?
Thanks
I've owned the MG III's and I've also had a friend (he's past away now) who owned the MG III's. Both of us switched to the Acoustat 2+2's because we both felt over all the Acoustat's are better.
The one thing you mention here are the MG-III's strong point. The Acoustat has very good highs in my opinion but they are not going to match the ribbon on the MG-III speakers.
Over all the Acoustat has more positives over the Maggie's but I'm sure you'll find Maggie die hards who will say the opposite. Both are good speakers.
What I felt the 2+2's had over the Maggies is both dynamics, lower bass and the ability to play louder. Both have good detail but the Maggies edge the Acoustat's out on the upper end and imaging due to the ribbon. The Three's being wider will image even less well than the 2+2's.
You could consider having your interfaces upgraded by Roy and possibly his "air" mod could help. However I'd obtain a pair of 2+2's or 1+1's which both image much better than the three's. (Yes I've owned the threes before too way back in the day)
I'm no expert but my two cents.
I've heard one of the larger Sound Labs (years ago so forget which model but they were close to six feet tall and almost three feet wide) compared directly against the 2+2's with the same amp and source material and the 2+2's beat um hands down. 2+2's really never got the credit they deserved in my opinion. Acoustat was one of the best and sad they went out of business..................
I agree 100% and that's not taking into account the difference in price Acoustat 2+2s in 1981 = $2,600.00 USA one hell of a bargain and the most important thing is = Reliability 30 years no problemo.
I'd like know about that one too as well as any other user-mods to MK121.
I've experienced the same thing as you converting from 121a to 121c but I had no opportunity to listen to them before and after in the same room.
So, I started taking snapshots of response/phase/distortion with HolmImpulse and then I'm going to undo the c-mod and re-measure.
Okay here is Roy's description of the Air Mod (Please note that I did not get the air mod because to me the high frequencies on my 2+2's already sound fine. Others have had positive things to say about Roy's upgrades including the air mod. I did have the other upgrades performed but only just recently. I could comment more later but others could probably chime in. Roy knows what he is doing:
--- About the Special Modification to your Acoustat Interfaces ---
You will notice that a small toggle switch has been added
to each interface, giving a choice of normal or “pure path” setting.
First :
Be sure that BOTH switches are set to the same position --
so that the sonic character of your left and right
speakers will be matched to each other.
Facing the interface, if the lever of the switch is set
to the LEFT the speaker will have normal factory response
and including the performance of all factory updates.
The modification is completely out of the circuit.
NOTE : This position of the switch (normal) is recommended to use
for the first two weeks of “burn-in” while the speakers charge up.
Your Acoustat speakers must be connected to live AC outlets at all times.
If the lever of the switch is set to the RIGHT the speaker
will have more detail and extension in the very highest frequencies.
Consider this a new tuning of the speaker. The resultant sound
is very exciting, especially on the best reference recordings.
Poorly recorded material will likely sound worse,
because of the increased detail. In addition, with this setting the
Rotary (or Sliding adjustable resistor) HF Balance control
is out-of-circuit and has no effect.
I like to call this the “Air” or “Rock-n-Roll” Mod.
It’s use seems most suited to Rock, Pop or perhaps Jazz.
Classical Music will probably sound best in the normal (left)
position of the switch. All a matter of personal preference.
For long life of the Silver switch contacts, it is recommended
to change the switch setting with volume off or at minimum.
Although an occasional A-B comparison “on the fly”
flipping of the switches, will not hurt anything.
--------------------------- Enjoy ! -------------------------------------
Roy A. Esposito / soundslikenew / mod start date : February 2008
--- About the Special Modification to your Acoustat Interfaces ---
You will notice that a small toggle switch has been added
to each interface, giving a choice of normal or “pure path” setting.
First :
Be sure that BOTH switches are set to the same position --
so that the sonic character of your left and right
speakers will be matched to each other.
Facing the interface, if the lever of the switch is set
to the LEFT the speaker will have normal factory response
and including the performance of all factory updates.
The modification is completely out of the circuit.
NOTE : This position of the switch (normal) is recommended to use
for the first two weeks of “burn-in” while the speakers charge up.
Your Acoustat speakers must be connected to live AC outlets at all times.
If the lever of the switch is set to the RIGHT the speaker
will have more detail and extension in the very highest frequencies.
Consider this a new tuning of the speaker. The resultant sound
is very exciting, especially on the best reference recordings.
Poorly recorded material will likely sound worse,
because of the increased detail. In addition, with this setting the
Rotary (or Sliding adjustable resistor) HF Balance control
is out-of-circuit and has no effect.
I like to call this the “Air” or “Rock-n-Roll” Mod.
It’s use seems most suited to Rock, Pop or perhaps Jazz.
Classical Music will probably sound best in the normal (left)
position of the switch. All a matter of personal preference.
For long life of the Silver switch contacts, it is recommended
to change the switch setting with volume off or at minimum.
Although an occasional A-B comparison “on the fly”
flipping of the switches, will not hurt anything.
--------------------------- Enjoy ! -------------------------------------
Roy A. Esposito / soundslikenew / mod start date : February 2008
If you don't mind my butting in...
I recently had Roy update the older (Blue) transformers on my 1+1s and I opted for the Air mod. Simply stated, it completely bypasses the variable resistor HF control. I will post a pic when I'm able to email them from my iPad - I'm having email issues right now.
As for me, I find it a valuable addition. It improves resolution without sounding "brighter". The top now matches my U-1s.
Wow....for some time i have been talking about droping the 500mg at the end of the Bias panel feed to 5-10 mg.....i have 3mg in now an the topend is the best i have ever had out of Any Acoustat mod yet......
looks like the so called Air mod has (No)meg ohms Res...At all....??
This will give you all the topend anyone well wont.....AnThis Air Mod setup of Lowering the Bias Feed megs... that feed the panels Work well with ML there stock setup is 60meg drop it down to 15meg...you have new an better speakers............
all the output gos way up....3-5db more output an sounds killer..
Also the Acoustats 121... Bass Transfourmer...Has a New gold dail 1ohm res..... thay are vary bright toney.....i have a two ohm in my setup i like it better...
Not sure Roy will like this pic....now anyone can do what he gets Big $$ for.....hehe
SL has No res.in there bias panel feed ......
thanks for the pic.....
looks like the so called Air mod has (No)meg ohms Res...At all....??
This will give you all the topend anyone well wont.....AnThis Air Mod setup of Lowering the Bias Feed megs... that feed the panels Work well with ML there stock setup is 60meg drop it down to 15meg...you have new an better speakers............
all the output gos way up....3-5db more output an sounds killer..
Also the Acoustats 121... Bass Transfourmer...Has a New gold dail 1ohm res..... thay are vary bright toney.....i have a two ohm in my setup i like it better...
Not sure Roy will like this pic....now anyone can do what he gets Big $$ for.....hehe
SL has No res.in there bias panel feed ......
thanks for the pic.....
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Milligrams (mg) ? Do you mean mF as in micro farads?
Actually it appears there is a fixed resistor used during bypass. What he bypasses is the variable control. I don't find the end result too bright.
It's quite easy for anyone to substitute a Dale resistor for another brand. These are heat sinked for longevity.
Because bias is under the control of a variable pot. Ever seen the back of an SL backplate?
Attached is a pic of mine. It's the control to the upper left.
My experience with Roy was exceptional in every way. Communications - Status updates - high quality work for a reasonable price. It certainly helps to employ someone with intimate knowledge of the product and design.
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Here are photos of mine but for me it's complete unknown the only thing i know is that the caps are Audience Auricaps 0.02 + 1-10% 5000 volts and the resistors are Caddock MS-322 that is all i know when it comes to mods all the work is done by my friend Jocelyn ME all i can do is LISTEND.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Well sounds good to me.....hay the gold dale may work great there.....But Dr west found the cast sand Chep 50cent res he uses in his crossover to sound better....that gold daie type cost 10 time as much as the sand DrWest uses......That why i Diy....i can make better...It ezey....but your not a Diy guy....
An yes there are people out there that can diy any thing..... so Roy has work...Thats a good thing....but most here can...just saying........hehe
Pic 2 is not your SL ther all close.....An in pic 1 you can see the 500m res....in the bias feed....
An yes there are people out there that can diy any thing..... so Roy has work...Thats a good thing....but most here can...just saying........hehe
Pic 2 is not your SL ther all close.....An in pic 1 you can see the 500m res....in the bias feed....
Attachments
![Acoustat_MK-121C_Interface[1].gif](/community/data/attachments/397/397032-78c32135ccd2e14f0a9acb11a320d6a7.jpg)
![SL_A1_interface_pic[1].jpg](/community/data/attachments/397/397034-1fd1c32f34a07a0c5ef781cc6e329d5c.jpg)
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Just curious.
Has Jocelyn explained why he (she?) uses a wall wart in the power supply?
I am not speking for Mr Acoustat ...but hes not a diy guy eather......
Thats was Acoustat last bias update....run off 12-15 v wall wort!.....But you can see the 500mg res in the bias feed to the panel....that can be dropet for better highs....AKA air mod...hehe
we have the older bias setup.................
Thats was Acoustat last bias update....run off 12-15 v wall wort!.....But you can see the 500mg res in the bias feed to the panel....that can be dropet for better highs....AKA air mod...hehe
we have the older bias setup.................
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