Perhaps everything just needs to break in for a while.
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Your new amp needs to break in. If the transformers are new, you should not really expect any magic for a few hundred hours. That's a lot of wire to break in, plus all the caps. I'll bet if you just wait it out, you will be pleased. I can't imagine your silver ribbons REDUCING the high end. It sounds like typical "new amp" syndrome.
By increasing the spacing between the positive and negative runs of a speaker cable further apart from each other, you increase inductance. Inductance in a speaker cable kills treble response.
If you want to keep the cabling that you have, try taking the two runs and spiral wrap them together. Due to the spacing between conductors that will still exist, you're still going to be on the inductive side, but this might help a bit. You'll probably have to replace these cables to solve at least a good portion of the problem. Sean
In addition to all the foregoing comments, it seems to me that silver (and silver alloy) cabling tends to accentuate the high frequencies. So if anything, your cables are adding to the HF extension, not detracting from it. Must be something else.
Essentially, it sounds like you have new (or newly replaced) tubes throughout your system. Give them a 35 hour week of regular daily play (that means at least 5 hours a day) and if beginning the second week, things don't start to sparkle, then it's tube rolling time!
I just went through the same thing. The interconnects were not the problem but the speaker cables caused a roll off at the top. My VAC PA100 did not have any problem with the silver ribbon (Audio Magic brand) speaker cables but the VAC PHI 110 did not match well at all with these cables. I replaced them with a hybrid silver and copper MAS Reference speaker cable which is a non ribbon design low inductance cable. That solved the high frequency roll off problem for me.
It wouldn't matter if the speaker cables were copper, silver, gold, platinum or unobtanium. It isn't the type of conductor so much as it is the geometry of the conductors. Given that most tubed amps are already lacking in high frequency extension, using such a design can only compound the problem. Sean
Sean, I've been using .005" X 2" copper ribbons as speaker cables and .005" x 1/2" copper ribbons as ICs with all tube equipment. I've tried spacing them close together or far apart and it makes no discernable difference. These ribbons sound much better with my tube system than a variety of round-wire commercial designs in various geometries.
While most tubed amps already have GOBS of inductance on the output due to the matching transformer, how discernable the added inductance from the loudspeaker cabling will be has to do with the overall frequency response of the amp, the stability of the amp, the bandwidth of the speakers and how well one can hear. What is discernible to some may not be discernable to others. What alters the sonics of some systems, may not alter the sonics on other systems. As a general rule though, increased inductance in a speaker cable reduces high frequency bandwidth and linearity.
Other than that, i don't doubt that the copper foils / ribbons sound excellent. Solid core conductors, minimal skin effect, heavy gauge for low series resistance, etc... These are all key ingredients to minimal signal degradation. Sean
Thanks for your response to date.
I'm currently using a pair of Osborn Epitome Reference with the extra bass units.
FREQUENCY RESPONSE of Speakers
Grand Epitomes 20 to 20000 Hz. Tweeter accuracy throughout operating range +0/-1db. Usable bass to 8 Hz.
CROSSOVER POINTS 125 Hz and 3500 Hz @ 12 db/Octave. Bass Unit @ 60 Hz.
MINIMUM IMPEDANCE 5.8 Ohm. With Bass Unit 3.9 Ohm.
REC. MAXIMUM POWER 200 Watts R.M.S per Channel.
REC. MINIMUM POWER 10 Watts R.M.S per Channel.
If the Interconnects are also Ribbons, this must make a difference to the highs. It's the complete combination. I'm going to plug my original copper based speakers cables back and check to see if discernable difference is obvious. Will Keep you posted...
What is a desirable impedance for speaker cables and what is desirable for interconnects are two different things. As such, using the same materials in the same geometry for both types of cabling can result in different problems in the circuit. Where those problems arose would depend on what geometry was used and where the resultant impedance was best suited for.
This is why i it cracks me up to see companies using identical cable designs for both their interconnects and their speaker cabling, as they should be quite different by design. Yes, the same or extremely similar materials can be used, but the geometries and net impedances should be measurably different.
As such, it's quite possible that your interconnects will work fine, especially with tubed gear that already has higher impedances to deal with. We are talking about thousands of ohms here. On the other hand, the amplifier / speaker portion is all of very low impedance, where just a few ohms can make a measurable difference.
Whether or not the speaker cabling is responsible for the majority of problems that you're encountering obviously remains to be seen. It's possible that you have other problems elsewhere in the system and you're running into a compounding effect. Sean
I suppose many of you are correct in saying the equipment just needs to burn in a little. I'm guessing if the SET amps are using the V-Cap capacitors, the waiting period may be even longer. Does anyone know the characteristics of V-Caps as they are burning in?
I'm also concerned about this oscillating problem when potentially using Ribbon based cabes in SET tube amps.
Sean, I was fooling around with some 9' DIY silver/cotton speaker cables & would appreciate your thoughts. Each phase is a 4-braid litz weave of four Audio Consulting 24 awg solid wire strands inside four 2mm cotton sleeves. I found that treble response became more extended when I twisted together the two 4-wire bundles representing the two phases (as compared to running the two phases separately across the floor.) Do you think it's worth going a step further, and weaving all eight strands of the two phases into one 8-braid? This would bring all +/- strands closer together and in a uniform geometry.
Dgarretson: Making a twisted pair lowered the inductance and nominal impedance of the cable as compared to running the cables spaced further apart. Since impedance typically rises with frequency in most audio circuits, making it harder to pass signal as frequency climbs, and inductance rolls off the treble response, the steps that you took helped to negate those potential problems. That's why you can hear the changes that you made in a clearly audible fashion.
Having said that, unless you can maintain near identical conductor lengths and a VERY consistent weave, i would stick to using the twisted pair configuration. Even going this route with multiple conductors can be tough. That is, it becomes difficult to control the internal geometry of the multiple conductors within each leg of the cable.
If you are trying to optimize a design using the parts that you've already got, you might want to try going the spiral wrapped star quad approach. This will require using two more cotton sleeves per cable, meaning that you would need four more total.
Use two conductors per leg and stagger the polarities of each leg. In other words, use 2 pos, 2 neg, 2 pos, 2 neg in an alternating circle arrangement. Once you've got the four individual bundles somewhat anchored together, apply a slight but consistent spiral twist to the entire length of the bundle.
This approach will lower your nominal impedance, offer improved power transfer, offer increased transient capabilities, broaden the bandwidth of the cable, reduce EM radiation from the cable itself, offer a reduction in potential RFI susceptability, etc...
This approach is about as good as you can get using what you have without getting far more complex and time consuming. Whether or not you like the end result would obviously be a matter of personal preference. Sean
PS... Your aggregate gauge size is appr 18 gauge for the four 24 gauge wires per polarity.