I should say something about my sonic frame of reference. When I talk about sound I relate it to live concerts I attend. I also, for example, am right now practicing flute on an 1884 hand made French flute. When I play horn it is a Missenharter 1888 cornet or my 1945 Besson Meha. My drums are German made Sonor with very old Turkish cymbals. I won’t go into my guitars. Bottom line is my ears are used to great sounding instruments.
You'd be better off just building a second Mod-86 amp for the second pair of speakers. At least you would have independent level controls for the two pairs of speakers. Driving two pairs of speakers in different rooms at the same time is a recipe for poor sound.
Cheers
Cheers
I already have a Mod86 for a separate system I love. I would like comparable sound from an amp capable of powering two pair of speakers.
If you really want the two speakers in parallel, the Parallel-86 is the better amp due to its higher output current capability. It'll drive a 4 Ω load without breaking a sweat, even on ±35 V rails. If you lower the supply voltage to ±28 V, it'll drive a 2 Ω load. Your timing is excellent too. I'm organizing a group buy, so if you get your order in by this Friday, you can have Parallel-86 boards. I might get a few extra boards, but don't count on the boards being available past this weekend. You can preorder bare boards here: http://www.neurochrome.com/product/parallel-86/
If you would rather buy assembled and tested modules, please toss me an email.
My preferred solution would be to have a MOD86 amp drive each speaker and just run the signal source to both amps. That way you can get independent volume control on the two sets of speakers. That would also set you up for something like an Apple Airplay or Sonos system.
Tom
If you would rather buy assembled and tested modules, please toss me an email.
My preferred solution would be to have a MOD86 amp drive each speaker and just run the signal source to both amps. That way you can get independent volume control on the two sets of speakers. That would also set you up for something like an Apple Airplay or Sonos system.
Tom
Tom,
I'd like two paralle86s and a power 86. Can't wait for the other two rooms to sound as good as the room with the Mod86.
I'd like two paralle86s and a power 86. Can't wait for the other two rooms to sound as good as the room with the Mod86.
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one amp running two speakers
I already have a Mod86 in a system in a rather remote room. Your suggestion makes sense but would require two more Mod86s and one 20 foot long pair of your pseudo balanced ICs. One amp would be in the 2nd floor closet and the other in the 1st floor room. I much prefer not having an amp in that room for aesthetic reasons.
I don't know what apple airplay or sonos systems are. I guess I'm living in the dark ages and it's probably time to learn about these online services and find what ones, with the appropriate device, would compare or exceed the quality of my ancient sources.
My sources are a Dual turntable, OPPO bdp-95, Meridian 506.20 and a Magnum Dynalb ft101A FM tuner. All those are connected to an Audible Illusions M3A. All are in the 2nd floor closet.
In the past, for powering two pair of speakers from one amp, i made a speaker selector box...the typical A or B or A+B and a separate volume control box for the 1st floor speakers. The selector box was in the 2nd floor closet.
The volume control box was mounted in one of the built-in benches on the sides of the 1st floor fireplace. The preamp controlled volume for both pair of speakers but the 1st floor volume control could be used to reduce the volume of the 1st floor speakers. It all worked quite well. I still have the units and will use, or modify, them for use with the Parallel86.
I could have made a volume control that would control both speakers but when playing both pair it was for background music. When, seriously listening I prefer just the AI M3A preamp with only the selector box in the line.
I already have a Mod86 in a system in a rather remote room. Your suggestion makes sense but would require two more Mod86s and one 20 foot long pair of your pseudo balanced ICs. One amp would be in the 2nd floor closet and the other in the 1st floor room. I much prefer not having an amp in that room for aesthetic reasons.
I don't know what apple airplay or sonos systems are. I guess I'm living in the dark ages and it's probably time to learn about these online services and find what ones, with the appropriate device, would compare or exceed the quality of my ancient sources.
My sources are a Dual turntable, OPPO bdp-95, Meridian 506.20 and a Magnum Dynalb ft101A FM tuner. All those are connected to an Audible Illusions M3A. All are in the 2nd floor closet.
In the past, for powering two pair of speakers from one amp, i made a speaker selector box...the typical A or B or A+B and a separate volume control box for the 1st floor speakers. The selector box was in the 2nd floor closet.
The volume control box was mounted in one of the built-in benches on the sides of the 1st floor fireplace. The preamp controlled volume for both pair of speakers but the 1st floor volume control could be used to reduce the volume of the 1st floor speakers. It all worked quite well. I still have the units and will use, or modify, them for use with the Parallel86.
I could have made a volume control that would control both speakers but when playing both pair it was for background music. When, seriously listening I prefer just the AI M3A preamp with only the selector box in the line.
Have you considered having a single switch, on or off, one on the second floor and one on the first floor? That way you can just turn on and off from wherever you may be listening.
Edit: Thinking about it is a bit apples and oranges. Your way works fine and you don't have to build any more boxes.
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This guy is building my DIFF PRE 8x2 and Modulus-86 into a table top. I figured I'd share. He's got some pretty creative woodworking going on. Same guy built my DG300B for use as a head phone amp to drive a pair of Audeze LCD2.
Project link: Audio Console (sorry, I couldn't get links to the pictures).
Tom
Project link: Audio Console (sorry, I couldn't get links to the pictures).
Tom
I saw his posts last week. His wood work is fantastic. Building a vacuum press is amazing. His work, overall, is stunning.
Measurements of MOD86 Rev. 2.1 and SMPS-86 attached. There is no meaningful difference in the performance of the MOD86 when powered by a well regulated lab supply (HP 6643A), a Power-86 + toroid (adjusted to ±24 V out at full output power), and the SMPS-86.
MOD86 + SMPS-86, Power out into 8 Ω: 28 W
MOD86 + SMPS-86, Power out into 4 Ω: 42 W
If you don't need a ton of power and would like to skip the mains transformer and all that mess, the SMPS-86 is a good way to go.
Tom
MOD86 + SMPS-86, Power out into 8 Ω: 28 W
MOD86 + SMPS-86, Power out into 4 Ω: 42 W
If you don't need a ton of power and would like to skip the mains transformer and all that mess, the SMPS-86 is a good way to go.
Tom
Attachments
My Mod86 has an Antek AS-3224 and Power86. Based on the above post it seems that if I replaced those components, with an SMPS-86, the wattage @ 8Ohms would drop from about 40 to 28 and at 4Ohms it would drop from about 68 to 42. Is that correct? Would the dead quite quality and other spec.s be the same?
Hmmm,.. I think I must have missed something.
Measuring from pin 2 of J2 to pin 4 of U4 I'm getting about -15v on all 4 boards, so that's good. But when I move the probe to pin 8 of U4 I get 0.00, I expected +15V.
Also, I was surprised to find that the output of power 86 is only +/-18V. Granted it has 4 mod86 connected to it, but with Antek 3222, I thought I would have +/-28V DC.
So since I have the same problem on all 4 boards, is it possible the problem is an error I made on power86 board? I'm thinking of swapping the power86 in my preamp tomorrow to see.
Any thoughts?
Clarify: I have two power86 boards. One is in my preamp and is known to function properly. The other is in the 4ch mod 86 I'm currently building. Should I swap the two power86 boards?
Measuring from pin 2 of J2 to pin 4 of U4 I'm getting about -15v on all 4 boards, so that's good. But when I move the probe to pin 8 of U4 I get 0.00, I expected +15V.
Also, I was surprised to find that the output of power 86 is only +/-18V. Granted it has 4 mod86 connected to it, but with Antek 3222, I thought I would have +/-28V DC.
So since I have the same problem on all 4 boards, is it possible the problem is an error I made on power86 board? I'm thinking of swapping the power86 in my preamp tomorrow to see.
Any thoughts?
Clarify: I have two power86 boards. One is in my preamp and is known to function properly. The other is in the 4ch mod 86 I'm currently building. Should I swap the two power86 boards?
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Maybe I got a bad trafo. It seems to be wrapped kinda weird. I part of the donut seems fatter than the rest.
I have another an-3222 (I bought two last year)
When I switch the multimeter to 200/600v (I think that's how I should measure AC, and measure from the green to blue, I should get 22V, right? It's less than that, 15 or 16 I think.
Mod86 requires at least +/-20 V to do the final check right? Maybe a bad trafo not putting out the correct voltage is why I'm not getting anything from J3 pin 2 to U4 pin8?
I guess I'll sleep on it, and think on it some more after work tomorrow.
I have another an-3222 (I bought two last year)
When I switch the multimeter to 200/600v (I think that's how I should measure AC, and measure from the green to blue, I should get 22V, right? It's less than that, 15 or 16 I think.
Mod86 requires at least +/-20 V to do the final check right? Maybe a bad trafo not putting out the correct voltage is why I'm not getting anything from J3 pin 2 to U4 pin8?
I guess I'll sleep on it, and think on it some more after work tomorrow.
Correct. The output power drops to 28 W (8 Ω), 42 W (4 Ω) with the SMPS-86 due to the lower output voltage.
With the SMPS-86, I measured 42 µV RMS (unweighted), 33 µV RMS (A-weighted) of output noise.
I looked briefly at the output mains hum. -110 dBV with the SMPS-86.
It does indeed look like the Modulus-86 really doesn't care what supply you use. The output power is lower due to the lower output voltage of the SMPS-86. This means the amp hits clipping at about 1.5 V RMS input. These are the only changes I foresee in the spec table when switching from the Power-86 to the SMPS-86.
Tom
You get 0 V on all four boards?
Disconnect the four MOD86es. Measure the output voltage of the Power-86. You should see ±30 to ±32 V. The voltage will droop under load.
Any chance you wired the primary for 230 V?
* 230 V: Red connects to live, black to red, black to neutral.
* 120 V: Both red wires connect to live. Both black wires to neutral.
More detail is available on pages 12-14 in the Power-86 design doc.
The Antek transformers are not renowned for aesthetics. I doubt you got a dud.
According to Antek's spec sheet for that transformer, you should have 22.7 V open circuit. If you get about half that, you have the primary wired wrong.
Yeah, but it should work well enough even with ±18 -- at least Rev. 2.0 will. In Rev. 2.1 I upped the voltage of the on-board regulators to ±17 V, so Rev. 2.1 will need ±20 V. Even if you apply ±18 V, you should still have some voltage on the +15 V (+17 V in Rev. 2.1).
I suggest testing the amp block by block. Start with the power supply. Once you have ±30-32 V out with no load, connect the amps. With four amps connected, I'd expect around ±28-30 V out of the Power-86 at nominal mains voltage.
Tom
GRRRR! Why didn't you come out with this last year
Actually, you did, when you designed your Diff Pre 1.0 😉
Great work...the SMPS-86 will be great for my future designs
Best,
Anand.
Yeah. That was a convincing proof of concept experiment. The bigger switchers are noisier, but the MOD86 doesn't care.
Great work...the SMPS-86 will be great for my future designs
Thanks. My plan is to continue to develop great circuits for the DIY Audio community. So far, so good.
Tom
