OT Crossover Wiring

[QUOTE=LowOhms;1970574]Way Cool report !! How precisely did you implement the wire? I like to pay 50 cents a foot, on eBay, low-balling sellers, for 12 AWG.
Hi Jeff
Nothing fancy to my setup, it's my bedroom system, 604-8Ks with the Markwart simplified XO, driven by a NAD C315 amp, music provided by Jolida CD-100 and a Perreaux tuner. Using 6ft lengths of the 12g twisted together, about 2 inches per twist, from amp to external XOs, twisted cables just sound better than straight runs. PIO caps linked with short runs of same 12g, at the output switched to 14g Teflon for both tweeter and woofer feeling that an all 12g setup might thicken the sound. An earlier post shows the XO just before the latest change.

For wiring fanatics:

Custom build for customer.

http://www.hostboard.com/forums/hbmc.../2017/03/7.jpg

Pass F5 Class A amp.

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Originally Posted by westend9

For wiring fanatics:

Custom build for customer.

http://www.hostboard.com/forums/hbmc.../2017/03/7.jpg

Pass F5 Class A amp.

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Whoahhh. I don't think that is well-thought out wiring at all. Its executed for eyes, not ears.

Here below, is how "I" , a DIYer, look at it, and others may look and interpret it totally differently, of course :

(1) look at the length of the lead ins, from the RCA jacks, to the input devices on the board, WAY WAY too long. ( In my DIY SETs, I try for 2 inches, or less to the control grid ).

(1a) Look at the close proximity, of the most delicate input wiring and RCA jacks, to the fields of the output wiring and connectors !!

(1b) Look at the close proximity, vertical panel right - rear side of the photo, of the 120 VAC LINE's INPUT receptacle, and 120 VAC wiring, and those fields, to both the RCA Input and Output wiring of that one close-by channel. Very poor and avoidable easy !!

The correct placement of the 120 VAC input's entry to this amp would have been the OTHER side of the amp, and there would be a short, non-polluting run to the power transformer. As done, the AC with its field, is running down the whole length of the amp, ( right side, bottom ) with its fields goofing up the audio channel. Totally avoidable with SOME thought. Some common sense needed to be applied !

(2) Do we really see a screw terminal plastic block, to connect the power transformer to the Supply leads ?? No soldering, no terminal block, just floating ( no. maybe secure, can't tell ) screw driver connections ?

(3) Look at all the wires, after the the screw driver connector, and how they are all touching each other, rather than floating across the chassis, and hopefully, not touching each other, at all !!!

(4) Worst of all is to use any sort of tie wraps, or wire bundling devices to make the wiring look " neat" as we all see, bottom rear, either side. That is always a mighty big NO NO in audio building.

(5) Why can someone like me, a lowly non-scientific Business Administration graduate, point these things out to others on a public Forum? I would think, the designer would have known how to lay out that amp better. Maybe he is real smart, builds to impress eyes, some ears, and SELLS a lot of stuff. Probably so.

These are just "my " opinions, expressed herein. Certainly, I could be wrong on all counts. I'm just a DIY hobbyist.


Low Ohms ........... Jeff Medwin

Being an aircraft electrician I appreciate neat wiring. Wiring is more than just point A-B, its also how it looks.
I think we can obey the proximity laws and make our wiring look neat. I know if I went inside one of my Ashly amps and cut all the zipties, and pulled the wiring out of the bundles, I would not be able to HEAR a difference. Nor do I think would the average audiophool

There are about as many ways to wire an amp as grains of sand on a beach, some better than others.

One criteria of the above example was the size of the case as dictated by the customer. It was pretty much a 10 lb sausage placed in a 5 Lb casing.

I've found no instances of any audiofoolery in having AC wires in close proximity. Typically, phases are opposite so that there is inherent cancellation of induction. The transformer was encased in it's copper and brass housing to eliminate inductive noise to the amp boards. The length of input and output leads to those boards, dictated by the placement of the high temperature devices on the heatsinks. This is a Class A amp so it operates at it's highest quiescent current when at idle. Believe me, temperature rules when biasing this amp.

I thought it might be of some interest to see the variety of different wire used inside the amp. Maybe not.

I don't see the obsession about not using a terminal block. They are made for exactly this purpose and others went before using similar process. I find it neater and more secure than soldering and laying wire in air space or laying them down within the case. Again, grains of sand.

About the only caveat I had in retrospect about "neatness" is that the input wiring could have become an antenna because of the layout. In use, that was proven to not be the case.

BTW, the input wiring from the switch to the boards (white) is teflon jacketed, teflon and copper shield, A Belden Product manufactured to use in very high frequency mil spec communication wiring. I've used it in a number of audio applications, including high-end SS preamps and it has shined in those applications.

Quote:

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Originally Posted by Elitopus1

Being an aircraft electrician I appreciate neat wiring. Wiring is more than just point A-B, its also how it looks.
I think we can obey the proximity laws and make our wiring look neat. I know if I went inside one of my Ashly amps and cut all the zipties, and pulled the wiring out of the bundles, I would not be able to HEAR a difference. Nor do I think would the average audiophool

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Hello,

Aircraft wiring you do, is not the same as audio amplifier wiring !! Never was, never will be.

I agree with you. " No detectable difference" may be the case in your Ashley amp, but it is not the case in a SET where there is no common mode rejection. I am talking apples, not oranges.

That which you state, "no detectable difference", also may be the case in an average guys' system.... or in a Push-Pull tube amp, which has common mode, .....not to detect a difference.

There are also many nuances that most amps won't detect, the vast majority of amps do not differentiate particularly well, which makes them average, and, it is often times to their detriment. What does that tell us? Yes, for sure, one's mileage may vary

Wire-dress certainly is a factor , audible, in the best layed-out and best designed gear.

Having wires touching, or in bundles, longer than necessary wire paths, wires not crossing at right angles, all degrades from the best possible sonic result.


We can choose, its a free country, we all have free will, as to do whatever pleases us, and use whatever equipment we want for our home's hi fi system, for source and powering. I am just explaining, pointing out to some who may have an interest, audio design factors - possibly things they were not ever aware of.


Jeff Medwin

Well, I know one thing, Jeff. your dogma about wiring is interfering with any type of design critique.

Tell me one thing--how do I get a 2" long wire to travel 6" to an amp board location? You can clearly see from the images that the output wires are set at the shortest possible length to reach the back plane of the amp chassis.

Edit: reread your post for clarity and I'm sensing a certain condescension. You can contact Nelson Pass and discuss with him the "averageness" or "differentiation" of his design. I know for a fact that certain builders of this amp design have pushed away their tube gear in favor of this Class A amp. I'm starting to get the feeling that someone is a "legend in their own mind".

Quote:

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Originally Posted by LowOhms

Hello,

Aircraft wiring you do, is not the same as audio amplifier wiring !! Never was, never will be.

I agree with you. " No detectable difference" may be the case in your Ashley amp, but it is not the case in a SET where there is no common mode rejection. I am talking apples, not oranges.

That which you state, "no detectable difference", also may be the case in an average guys' system.... or in a Push-Pull tube amp, which has common mode, .....not to detect a difference.

There are also many nuances that most amps won't detect, the vast majority of amps do not differentiate particularly well, which makes them average, and, it is often times to their detriment. What does that tell us? Yes, for sure, one's mileage may vary

Wire-dress certainly is a factor , audible, in the best layed-out and best designed gear.

Having wires touching, or in bundles, longer than necessary wire paths, wires not crossing at right angles, all degrades from the best possible sonic result.


We can choose, its a free country, we all have free will, as to do whatever pleases us, and use whatever equipment we want for our home's hi fi system, for source and powering. I am just explaining, pointing out to some who may have an interest, audio design factors - possibly things they were not ever aware of.


Jeff Medwin

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The amp in the pic a couple posts up is not a SET amp. That is the amp in question since you criticized how it was wired.

Quote:

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Originally Posted by westend9

There are about as many ways to wire an amp as grains of sand on a beach, some better than others.

One criteria of the above example was the size of the case as dictated by the customer. It was pretty much a 10 lb sausage placed in a 5 Lb casing.

I've found no instances of any audiofoolery in having AC wires in close proximity. Typically, phases are opposite so that there is inherent cancellation of induction. The transformer was encased in it's copper and brass housing to eliminate inductive noise to the amp boards. The length of input and output leads to those boards, dictated by the placement of the high temperature devices on the heatsinks. This is a Class A amp so it operates at it's highest quiescent current when at idle. Believe me, temperature rules when biasing this amp.

I thought it might be of some interest to see the variety of different wire used inside the amp. Maybe not.

I don't see the obsession about not using a terminal block. They are made for exactly this purpose and others went before using similar process. I find it neater and more secure than soldering and laying wire in air space or laying them down within the case. Again, grains of sand.

About the only caveat I had in retrospect about "neatness" is that the input wiring could have become an antenna because of the layout. In use, that was proven to not be the case.

BTW, the input wiring from the switch to the boards (white) is teflon jacketed, teflon and copper shield, A Belden Product manufactured to use in very high frequency mil spec communication wiring. I've used it in a number of audio applications, including high-end SS preamps and it has shined in those applications.

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He should have mounted the transistors two inches higher on the heart sink, raising the PC boards by that distance. He could add a $5.00 bracket, at the top of the amp, with a plexiglass plate bolted to it. The RCA input signal jack could be mounted on that plexiglass ( double insulation ) plate. The amplifier's top cover could be plasma cut during construction, to allow the end user access to the RCA jacks. Lead length would be direct, and maybe two inches, or less.

Its almost a FREE better-engineering solution, using an open mind, common sense, and its from me, a business major. The boards will also be further-distanced from the power transformer.

He needs to place the AC outlet, some wheres on the opposite side of the amp. And use a 20 A. IEC, not a crummy typical 15 A. one.


Low Ohms, .......Jeff Medwin

Quote:

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Originally Posted by LowOhms

He should have mounted the transistors two inches higher on the heart sink, raising the PC boards by that distance. He could add a $5.00 bracket, at the top of the amp, with a plexiglass plate bolted to it. The RCA input signal jack could be mounted on that plexiglass ( double insulation ) plate. The amplifier's top cover could be plasma cut during construction, to allow the end user access to the RCA jacks. Lead length would be direct, and maybe two inches, or less.

Its almost a FREE better-engineering solution, using an open mind, common sense, and its from me, a business major. The boards will also be further-distanced from the power transformer.

He needs to place the AC outlet, some wheres on the opposite side of the amp. And use a 20 A. IEC, not a crummy typical 15 A. one.


Low Ohms, .......Jeff Medwin

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You truly are not looking at the layout of this amplifier and understanding some of the design criteria. You repeat that 2" thing like aliens brought it to the Egyptians. There is no possible placement of the amplifier boards that would accommodate the use of a 2" length of wire. The boards are approx 6" in length and there are positions of connections that prohibit the use of a such a small length. Further, a short length isn't necessary to carry the signal to/from the amp board. What's more important is that the junction temperature of the main devices be dissipated as efficiently as possible, i.e. no, they can't be raised to accommodate a 3" shorter wire. This is just foolishness, I'm now understanding. It is like teaching pigs to sing--it's difficult and the end result doesn't sound that good.

BTW, this will be my last post where Jeff Medwin has any type of discussion about or within.