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In Reply to: RE: In my direct-coupled 45 amp....some observations posted by coronadope on March 03, 2017 at 17:42:30
In 20-20 hindsight, its a shame you didn't just unsolder two of the three paralleled TCSS from the plate and B+ leads, going to the primary, and listen to that first. Oh well, I may have done the same. Do you use three TCSS on the OPT XFR's secondary ?? With the OPT XFR's step-down, that is a high current path, and it may be beneficial there.
TCSS is nicely made multi strand copper wire, I think in a teflon jacket. 19 AWG as I recall. Decent stuff. Its seven strands of 5N copper, three different gauges.
We have been playing with Mil Spec M22759/11 lately, and I just layed-in a supply of various AWGs to try out. If you would send me your address, I will be happy to send you some, just for me to find out what you hear !!
In the past two or so years, I have been routinely using DOUBLE 12 AWG of this Mil Spec wire ( copper multi-stranded, silver plated, teflon jacket ) into high current areas of my amp. As it turns out, I was WRONG to do so, ...so heavily. Although the double 12 AWG played with fuller dynamic contrasting, too much of this wire will lose the highs.
Under the advice of Mr. Dennis Fraker, I will be using less AWG in various spots, in all my future builds, in an effort to keep the lovely highs intact. I bought about 1,600 feet of various smaller gauges of the Mil Spec wire, two weeks ago. It will be incorporated in my upcoming build of JJ 2A3-40 mono amps. Again, Coronadope, happy to send some to you, need an address.
I will let someone else comment on twisting and not twisting...these IS an audible difference I have been specifically told, for several months now.
( Too heavily wired ( my first ) SET 45 amp, as of 04-2015, shown in photo. Since then, amp has been disassembled. )
drlowmu, One thing that stands out to me in your posted pics is the poor quality of soldering, especially those terminations involving thicker wire.
Lots of information available via Google on how to know what constitutes a good solder joint and how to achieve it.
This is more important than all of this wire nonsense.
Looking at the above picture, in this thread, I have NO idea how you can state what you do. Are there some other pictures you can highlight, and show me where you think I am errant ?? That would be helpful. Many thanks.
Jeff, simply by observation and knowledge/experience in such things.
I see blobs on tube-socket terminals, blobs/balls else-ware, excessive solder wicking along wire, dull masses of solder on multiple-component terminations, and the terminations on the rats-nests of component leads, e.g. chassis RHS/above centreline is very poor practice and likely
to have dry-joints.
Attached is a solder joint inspection guide and also a pic showing good soldering work.
I hope you find this helpful.
What does your term " Chassis RHS / above centerline " mean, stand for ??
Off Topic :
The amp you choose to show us, is a very poor example. Oh, I will grant you, the soldering looks fine.
But this is the SET Forum, and there are HUGE and numerous mistakes, in that amp's LAY OUT. It is a good example of what NOT to do, in SET construction.
Only the unintiated would be impressed by that amp's underside photo. We have to LISTEN to a SET amp, and not LOOK at its wiring. Here, briefly, is what I see, as poor lay out and design practice, in this photo :
(a) Wires touching, indeed even bundled. One never has wires touching each other in SET lay out. In Push-Pull, there is inherently more bandwidth, so, one can do this. Not in SET. I see seven tie wraps, where there should be none. Wires should never touch, and cross at right angles, when necessary. NEVER would one bundle different wires together - into a group.
(b) The use of a component PC board. All this does, is ADD to lead lengths, which should be kept as SHORT as feasible in SET lay out. Point to point rules in SET lay out, with the lengths of the components REDUCE the needed lead lengths. 'Takes thought to position / envision it, but " form follows function".
(c) Non - optimized wire gauge choices. Throughout the entire amp. The red twisted pair on the far-left, AC leading to the power transformer's primary, could be more robust, advantageously. Observe the tiny wire gauge off of the power transformer's high voltage secondary ( red-black-red ). See how TINY that wire is ? This creates a loss in dynamics, peak instantaneous dynamics, which makes the amp no longer fun to listen to.
Also, we now know in 2017, complements of Jack Elliano and Dennis Fraker, not to twist the high voltage secondary leads of a SET amp together as shown, if we seek best sonics.
Getting back to my soldering: I agree with your observations. In the past, I have used large ( often 12 AWG ) wiring, and too-small of an iron. As of December 2016, I have gone to a new, more powerful soldering gun, which should give me what I need, heat and heat control-wise. I also stopped using mostly " one size fits all, 12 AWG wire ", so as to retain more of the highs in SET builds I do. I will read your provided tutorial, thank you, and proceed as I can. Regards,
The pics can be loaded into your favourite picture viewer and enlarged to get a better look.
A good guide on soldering, below.
The Weller website is worth a visit.
The secondary wires on that model of EP output transformer are the winding
wires. So I "let it be" and wired directly to the binding posts.
(A side note to anyone reading this far)
I've been hearing and reading some very good things about the new Pioneeer
PLX1000 direct-drive turntable. Everyone's selling them for $695 or so.
Ready to take the plunge I went down to my local Guitar Center to check one out, $695. I politely asked the salesman if he could put it on sale for me and five minutes later, after consulting with his manager, $597.99!
Lovely. It says " Ask and ye shall receive, knock and it shall be opened unto you. " Mr. Fraker suggests, with that table, the top-of-the line Extreme Audio SPEED Carbon Graphite mats, with a " donut " gets it to go at a whole new level. You know that money you " saved Tom ?? ".... LOL.
Jeff .... Dr.Low Mu
Kinda off thread but ...do you take the ESR of each cap into consideration when you parallel capacitors ?
ESR ?? No, just EAR.
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