Using 4 ohm tap or 8 ohm tap

[Deang]

Where did I say it would be "technically impossible" to hear a difference? I said you might or might not hear a difference. At any rate, I was giving you grief (paybacks are hell:)

[meagain]

Maybe because I was expecting it. (darn forum's been down so long I lost my comeback mojo)

[meagain]

So Dean - you have Khorns, Peach, VRDs, and hopefully, your networks.... Have you tried this for kicks? And, do you still have that Behringer DEQ to play with?

[NOSValves]

Dean - I switched the VRDs from 8 to 4. Yes, I hear a difference. Noticeably and instantly. I don't much care anymore if you think this might be technically impossible or not. Nope.

[6]

You will hear a difference and in your case it maybe for the better. But its a band-aid not a true fix.

[Deang]

"So Dean - you have Khorns, Peach, VRDs, and hopefully, your networks..."

Hmm. Well, I also run Al's Trachorns, JBL 2470 midrange drivers, and Beyma CP-25 tweeters. I run several different networks, but my V-cap loaded Type A's spend more time in my system than the others. My listening area isn't very big, and since baby Alexia has shown up I don't drive the system to the levels I used to. Still, it gets plenty loud enough when the house is empty, and the Khorns maintain their composure without sounding compressed/pinched, or harsh. Experience over the last year has led me to believe that the better the horns and drivers are, the less network you need. The only exception that I can think of is the loading problems associated with large rooms, and the higher power requirements of these rooms really necessitate the use of higher order filters. I still believe that in their stock configurations, the Heritage speakers all sound much better with the ALK or ALK Jr.

"...Have you tried this for kicks? And, do you still have that Behringer DEQ to play with?"

The Super AA or ALK Jr. doesn't show ruler flat impedance to the amplifier like the original ALK. It actually moves around a bit, fluctuating between 6 and 14 ohms. However, the part values are scaled to 8 ohms, and when I run the network I use the 8 ohm taps. I've never tried the 4 ohms taps.

My son stole the Behringer from me. The only time I use it is when I need the RTA, and then Austin brings it over.

[meagain]

You have a constant impedance network and those sound better on the 8 ohm taps.

Dean (or anyone).... by 'constant impedance' do you mean the impedance is set to a fixed point? Are the stock AA's a 'constant' network also? And - where is this constant set to? Is it prohibiting the khorns from going below 8 ohms? Or do they allow it? I would think it would be nice if they allowed for it? Am I making sense?

I'm not sure if what I'm hearing on 4 is technically possible. But I'm always happy to hear a change in my system as there's a tendancy here to make changes and not hear much. When I changed to 4, I perceived 'bassyness'. I thought I was catching a few other nuances also, but focused on the bigger things. The bass & the vocals/higher stuff. It seemed to me that the vocals and other parts in the upper realm were too soft. I assume this is because of the perceived bass increase. An unbalance?

Then it occurred to me that I've been on xover setting 4/x for a while now (which I hate to do cuz I feel 'it's' a bandaid and taking things away from me).... My gut wants to switch back to 5/2 for this 4 ohm setting which would balance it out more? Then again - that might put me back to square one again as changing to the 4 ohm tap on the amp is semi-akin to changing the taps on the crossovers? []

You can now tell me I'm hearing things and laugh. That's ok cuz I had fun & this amuzes me! []

[meagain]

"So Dean - you have Khorns, Peach, VRDs, and hopefully, your networks..."

Hmm. Well, I also run Al's Trachorns, JBL 2470 midrange drivers, and Beyma CP-25 tweeters. Oh yea - I forgot. I run several different networks, but my V-cap loaded Type A's spend more time in my system than the others. What is a V-cap? And, if I remember - many prefer the A's but they can make the high's brighter? yes? My listening area isn't very big, Same room size as mine - deep. and since baby Alexia Great name! has shown up I don't drive the system to the levels I used to. Still, it gets plenty loud enough when the house is empty, and the Khorns maintain their composure without sounding compressed/pinched, or harsh. It must be the Trachorns? Experience over the last year has led me to believe that the better the horns and drivers are, the less network you need. You told me you went more minimalistic on mine. Perhaps I need more 'stuff'? The only exception that I can think of is the loading problems associated with large rooms, and the higher power requirements of these rooms really necessitate the use of higher order filters. I still believe that in their stock configurations, the Heritage speakers all sound much better with the ALK or ALK Jr.

"...Have you tried this for kicks? And, do you still have that Behringer DEQ to play with?"

The Super AA or ALK Jr. doesn't show ruler flat impedance to the amplifier like the original ALK. It actually moves around a bit, fluctuating between 6 and 14 ohms. However, the part values are scaled to 8 ohms, So because of the part values, this might quell this inherent fluctuation? Wouldn't it be better to use part values that go down to at least 6? Would that be better? and when I run the network I use the 8 ohm taps. I've never tried the 4 ohms taps. Could you try it for kicks & giggles?

My son stole the Behringer from me. The only time I use it is when I need the RTA, and then Austin brings it over. We're going to hook ours up this weekend to get some room readings to find out how horrifying my room is. Should be interesting and I hope it at least 'helps' to prove things either way and also guide me to where my room issues lie.

[NOSValves]

(which I hate to do cuz I feel 'it's' a bandaid and taking things away from me)

This is your entire problem you "feel and think" but rarely listen to music or your advisors like you should. This weekend we tapped all setups in my display room way down from the settings from my own room. There is no absolute right setting the only setting that is correct is the setting that sounds best. I've never met someone so guided by preconceived notions and wanting total absolutes answers in my some what short audio career. I wish I had a magic wand.............

Craig

[gonzp]

Craig with a magic wand....lmao than would they call you the amp ferry?

[meagain]

(which I hate to do cuz I feel 'it's' a bandaid and taking things away from me)

This is your entire problem you "feel and think" but rarely listen to music or your advisors like you should. This weekend we tapped all setups in my display room way down from the settings from my own room. There is no absolute right setting the only setting that is correct is the setting that sounds best. I've never met someone so guided by preconceived notions and wanting total absolutes answers in my some what short audio career. I wish I had a magic wand.............

Craig

I have no idea why you say that or where you're getting 'preconceived notions' from, nor what I've posted that lends itself to that thinking. I don't care for tap 4/x. I feel it's taking some stuff away from me. But it chills out 5/2, so I almost have no choice. In a perfect world, I'd stick with 5/2. But my world isn't perfect here. These are my impressions and what I hear regarding the tap issue and are certainly not parroted from anyone. In fact, I think if you did a search - you'd find a great many that are very happy with 4/x. Further, I've never read that 4/x removes anything from the mix. But I feel I lose some detail & nuances I had with 5/2. I've never waived in my opinion on this. This is my opinion as to what I hear.

I also feel Khorns have better bass than LaScalas. Because that's what I hear here. []

[meagain]

4 Ohm isn't working for me here. There's just something odd about it. The bass seems a bit 'more'... But I think 4 is detracting from important things. There's something duller/flatter to me. I'm listening to Sinatra and his vocals seem more cardboardish. And the horn sections don't seem attenuated right? As if they're not handled properly. Just something odd about it. Maybe I'm missing dynamics.

What's really wacked is when I first tried 4 ohm briefly earlier today, I quickly had the impression in my head that there was some weird fade in/out of certain frequencies/instruments. Like a semi-cutting out or diminishment when there shouldn't be. Upon relistening for a longer time, I'm pretty sure of it. As if something electronically bad is happening. Some weird phasing deal? Something electronically wrong somehow. It bothered me enough that I worried and switched back to 8 ohm. Darn.

[:|]

[Deang]

What is a V-cap? And, if I remember - many prefer the A's but they can make the high's brighter? yes?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

The V-cap is an oil impregnated metallized polypropylene using virgin film, hermetically sealed inside a solid brass canister, with soldered leads similar to the way Jensen does it. Expensive, and cost prohibitive for use in filters with high part counts or employing high values. However, doable with an A Type filter that only uses 2 capacitors. http://www.v-cap.com/oilcapacitors.html

It must be the Trachorns?

Lower distortion and the effortless quality are from the combination of the Trachorns bigger throat and smoother launch of the sound off the mouth of the horn. Im also using a true 1 exit driver mated to a 1 throat. With the K-55 and K-400/401 this isnt the case, where the exit of the driver is ¾ and the entry to the horn is 5/8. BTW, check and see if you have the rubber washers between your K-55s and K-400s. The washers are important.

You told me you went more minimalistic on mine. Perhaps I need more 'stuff'?

Your network uses a first order bandpass on the midrange, whereas the ALK uses a second order bandpass. So, yes, a couple less parts in the midrange part of the filter. The Jr. has a midrange that sounds more like the Klipsch filters its a bit forward and opens up very fast. However, its much cleaner sounding. Now, if you find the midrange too biting for your taste, then yes you might consider a move to the original ALK, which does sound more refined and smoother through the midrange. However, for about the same amount of money you can get a set a Trachorns. You already have a good network go for the new horns. Heck, might as well youve done everything else!

So because of the part values, this might quell this inherent fluctuation? Wouldn't it be better to use part values that go down to at least 6? Would that be better?

No. Variation in impedance is completely normal. It is only when it swings back and forth to extremes, unchecked that the sound can be impacted. Complex subject really. At any rate, keep in mind that your network was modeled out with state of the art software by someone who knows what hes doing.

[meagain]

Dean - I don't see any rubber washers between the k55 & horn. Should this be visable? I see only a black rubber 'band' around the driver/grey bell on the one I checked. Looks like it's just sitting there for no reason. I don't see anything else.

Do you know of any other caps that might suit me better than these 2 little solens? I never see anyone else who has them and even if I do a google search, it seems everyone complains about Solen. They don't seem to distinguish between types/colors in their gripe sessions. Yes, this makes me ponder. Is there any tweak I can do/have done by you that might pretty up the higher end for me but still retain the good parts?

I'm not up for changing horn types, etc. at this time.

[Deang]

I don't see any rubber washers between the k55 & horn. Should this be visible?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

The washers sit between the drivers and the horns. You'll have to disconnect the squawkers from the networks, and then unscrew the drivers from the horns. The washers should be plainly visible inside the throat of the horn. If they aren't there, you'll see metal.

Do you know of any other caps that might suit me better than these 2 little Solens?

No, not really.Dont get hung up on brand names. Whats most important is materials and construction.

Those two caps aren't so "little".

Solen (black), metallized, 2.2uF, 250vdc, 14 x 25

Auricap, metallized, 2.2uF, 250vdc, 20 x 23

Solen (white), film/tin foil, 2.2uF, 250vdc, 24 x 38

AudioCap Theta, film/tin foil, 2.0uF, 200vdc, 24 x 32

I never see anyone else who has them...

Yes, Im pretty sure youre the only one.Seriously, theyre good stuff. I dont think anyone around here is as anal about caps as I am, so you need to quit thinking about it. For cryin out loud, youve got my personal networks! I used them when I built my own ALKs, and those were eventually sold to Carl G., whos been real happy with them. Ive used them in several sets of Cornwall ALKs Ive built for others no complaints there either. Finally, quite a few high end type manufacturers use them too. If there was a way to get them faster, or if I had the money laying around that I could stock them in quantity I would use them all the time.

and even if I do a google search, it seems everyone complains about Solen. They don't seem to distinguish between types/colors in their gripe sessions.

Those comments relate to their metallized type. Since the film and tin foil version is only available direct from Solen in <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Canada, most just go for Thetas or Hovlands.

If you want to rule out the networks as a source of any dissatisfaction you are having with your sound, and you want someone impartial to render a verdict why not send them to another forum member for evaluation. Preferably someone who thinks its all smoke and mirrors and that I sell snake oil. I prefer harsh critics or skeptics, or someone that uses the competition. Heck, why not send them to BEC? I think hes wanted to hear them anyways, and can also run them through his spectrum analyzer to find out if theres anything wacky going on.

I still think your ears are sensitive to whats coming out of the K-400. Good networks, regardless of type or parts utilized dont make near the difference better drivers and horns do.

[Erik Mandaville]

Meagain:

Solens have been around for a long time, and I have used them for a long time. I also have liked them for a long time -- very good quality for the money

I used terminal strips for everything, although I used to use silicone rubber when I glued caps and coils to boards. They provide better vibration absorbtion than any kind of glue I tried. I just hate the way it looks.

First is the network I'm using, with Solens all around. I've been building these things for years, and have also used Hovlands, and the Solens work fine for me.

Second: The last tube preamp I made, with Solens used for coupling.

[Erik Mandaville]

preamp with Solens. Another forum member sent me Hovlands as a gift for something I helped him with, and I put those in. Both sound good, the Hovlands maybe slightly edgy -- still good.

The single most important factor is what you prefer. That's why a variable network is something I proposed to you before. The switching part is easy. If you want to try three different types, just let me know. I can put the other two in, install a switch, and you can decide for yourself.

[pauln]

I have read of another way of thinking about the relationship between the sounds of using different taps on the amp: When 'under-tapping' (8ohm speaker on 4 ohm tap) the resultant sound is more of comprised of the contributions of the amp rather than the speaker, when 'over-tapping' (8ohm speaker on the 16ohm tap) the speaker itself contributes more to the sound.

Therefore, if your speaker has an inate good sound, go with the higher tap (almost all SET listeners with horns in Japan do this); if the speakers inate sound is less than stellar, use the matching tap or under tap to allow the amp to have more control and contribution to the sound.

Does this square with electrical theory, and does it represent experimental experience? I find that the LS on the 16ohm tap have a captivating sound, but some source content like harpsichord music can be a little intense in the high end. I find them on the 4ohm tap to be a little dark and distant. The 8ohm works for me - best overall range dynamics, color, and impact. I noticed the same when I had Heresy.

BTW, the '8ohm' tap on the Wright SETs' Megnequests is actually 9ohm.

[kajh]

Hi all.

I have a McIntosh 602 SS amp with the usual 2/4/8 ohm taps. At the moment I'm running a pair of RF83's on the 8 ohms taps but after reading this thread I want to try the 4 ohm taps even though it seems to be tubeamps only that is mentioned in this thread. Does it matter at all of you have a tube or SS amp? I dont want to break any of my gadgets

cheers

[Guest " "]

moving from 8 to 4, will reduce the sound level by 3db.

see attached pdf for other ideas.

McIntosh%20Autoformer%20Training%20Page.pdf

[WMcD]

I'm not sure I agree with Mark. I certainly stand to be corrected. And I'd like to understand more with his good observations.

The point I don't quite agree with is his desciption, which seems to be saying that putting the speaker load on one tap or another varies the operating point of the tube. If that is what he is saying.

Let's take an SET amp. The tube is always in a conducting state when set up properly. This current is set by the bias on the grid with no signal input. That is the operating point in a quiescent state. There is a DC or zero Hertz signal in the primary of the output transformer. Essentially there is a loop which includes the power supply, the plate, the transformer and the cathode.

When a signal is applied to the grid, there is a variation in the plate current and therefore the current in the primary of the output transformer. Of course this induces a voltage into the secondary to which is attached the speaker. No d.c. or zero Hz comes through because the transformer coupling depends on a variation of the magnetic field in the core.

How much variation current flows in the loop at audio frequencies is indeed dictated by the impedance of the primary at that freq, and this is dictated by which output tap is used (and the speaker impedance). However, this is a variation of current only somewhat away from the quiescent (d.c.) operating point of plate current. The current goes plus and minus from quiescent current, which is fairly high as a start.

Therefore, the load on the secondary does not affect the bias of the tube. If it did, we might adjust bias at the grid, which establishes plate current, for different loads. I think we do not.

= = = =

There are though, I think, various effects on the speaker of using one tap or the other. This getting OT, but important.

One is that the amp, particularly an SET, has an apprecable output impendance. That means there will be some droop in output voltage at frequencies where the impedance of the speaker is very low.

Using a 4 ohm tap: We may be getting less voltage drive to the speaker. But the 4 ohm tap will deliver less variation in output simply because stepping down voltage this way, increases current capability, with less a.c. voltage. The output impedance is lower on the 4 ohm tap. Therefore there is less droop in output when the speaker has a low impedance This also, though, means there is a higher damping factor. This could be good or bad.

And, while we are stepping down the output voltage overall, we are also stepping down the inherent noise of the amp. You can turn up the input to the amp (and thus the output) without increasing the inherent noise within the amp. So this is a good thing for noise.

Using the 8 ohm tap: Here we have a higher output impedance and potentially more voltage at a light (high impedance) load condition, but more droop at variations to low impedance.

The change is that the damping factor has changed in the speaker loop. It is less damped with a lower damping factor.. Therefore at bass freqencies where the bass driver resonates (high electrical speaker impedance), there is more (relative to midrange) acoustic output for lack of damping by the amplifer output impedance. So we get a bloom of bass. This may be something you want, or don't want. But there is a difference.

= = = =

For the record. T-S speaker design assumes the use of an amp with a zero output impedance. That is to say that when Qes of the driver is calculated, it assumes the amp driving it is a dead short, or has an infinite damping factor. We're monkeying with that with SETs and transformer taps to the extent the output impedance of the amp varies.

It is interesting to see that even horn design takes the output impedance of the amp into consideration. If you look deep into the optimal throat size equation, this an assumed amp with zero output impedance. Don Keele points it out with n=1. And Wente and Thuras has the n factor. Of couse that is the midband where throat impedance is high.

I suspect that the Klipsch horn designs are acting more like a sealed enclosure down below Fc where throat impedance is low but finite. Note that the system resonance of a Khorn is below Fc. Therefore, less amplifier damping (the 8 ohm tap on an SET) may indeed increase bass. Or at least bump it up where we need a bump

= = =

Gee, this has wandered OT.

Comments invited, naturally,

Gil

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