[Emsquare]

I recently changed one thing that's absolutely blowing me away – I dropped the transition frequency between my 3.7s and subs to 40Hz. My, oh my, can I dial in a serious foundation now! The valves haven't registered any complaints about the extra work and neither have the Maggies. The only frustrating thing is the inconsistency from album to album. I have yet to incorporate a solution which affords level adjustment from my listening chair – a situation in need of redress. I'd really like to build a more specific crossover now, but I also decided to take on a couple new woodworking projects. I'm not the fastest gun in the west, but I enjoy fiddling around with this stuff

Bass is like that isn't it? It seems like a foundation for the rest of the spectrum. Have you tried a warble tone disc for that? Admittedly I haven't gotten around to selecting any acoustic measurement tools. But you tend to end up adjusting by ear in the final step anyway so you can try skipping to the end step and see what it gets you. The Michael Knowles test disc is a free download at binkster.net. Now the lowest warble tone is centered at 80 Hz. but it was subjectively effective to set my crossover point of 50 Hz. so it might be useful. Just a thought.

You sound like you are pretty happy with the remodel. You have that 'Got something accomplished' glow in your writting.

[josh358]

[deleted]

[josh358]

Safest maybe but easiest? IMHO we might be talking about snipe hunting with this endeavor. I don't even know that it there is any substance to it. And I only recently learned that there actually is something called a snipe...

Cute, yes?

It never ocurred to me to use a relay that way but it would be a way of doing it. I might even be able to do a DIY one. The only reason I have any interest in it is that it is somewhat controversial and it seems like it would be pretty easy to take it off of the table as a factor. But how to do it without making it an enormous waste of time? I'll look around on Wima's literature for their X2 caps or find a predesigend filter that uses them this way I suppose. As for the speaker fuses... Perhaps a .1 to a .47 uF would be sufficient for the purpose? Or I could just replace everything with a handful of 15A fuses for an evening and assume there will not be an event for the test period.

I so look forward to the days when I have the time and enrgy to teach myself to be a DIYer. (is that a word?) I can play part time hack for now and I have no idea why I find it so entertaining.

It's a lot of fun, isn't it? So much so that I ended up doing it for a living.

[SteveFord]

I like Davey's polyswitch idea.
Has anyone tried these in Magnepans?
I don't blow a lot of fuses but it would be nice to not have to dig around to find another one.

[jk@home]

Word of caution with the Dueland resistors, they are very fragile, leads breaking off (or maybe I'm just a bull in a china shop).  Ended up gobbing silicon at the end of the resistors to prevent this from happening again.

[Emsquare]

It's a lot of fun, isn't it? So much so that I ended up doing it for a living.

How did you manage to do that? I'm glad for you Josh. Some days might not have even seemed like work I would imagine.

And for the real reason I came back to this thread... This sums up what I went looking for in regards to fuse decoupling.



This is a snippet from a Hafler XL-280 manual that jives with a couple of other suggestions for this. They mostly like the metal film (self healing) or ceramic .01μF for speaker fuse bypassing. Make of the manual snippet what you will but of all things I don't care to spend time pondering is flipping fuses. So ... I will be adding the small number of caps to my Mouser cart for the next order. And I really like Mouser for this kind of thing. Mouser, Parts Express and Parts Connexion covers most anything I've ever gone looking for as an audio parts source.

I should have stuck with trying to poke fun at stuff. I was having a lot more fun doing that.

[josh358]

Basically by accident. It was after college and I was happily sitting around doing nothing, so happily in fact that when my mother met a guy who ran a sound studio at a party and he mentioned that he was looking for someone she said "Hire my son!" So much for job fairs, eh? It was never like work. I mean, there was a lot of pressure and long hours, but basically it was lots of toys and million dollar budgets to spend on your hobby.

I confess that I'm a conservative when it comes to speaker fuses, but that Hafler manual pretty much reinforces what I'd thought. I think I'd want to try it first, preferably in some kind of blind test, before I'd take the risk with my own speakers. It's not that I blow fuses these days, but accidents do happen.

[SteveFord]

Yesterday I had a Winged "C" 6550 decide to go "Good-Bye Cruel World" and it made me think of this thread.  I know it's about resistors but fuses kind of crept in somewhere along the line.
At any rate, the fuse in the amp took the hit but I do find the fuses in the speakers comforting.  I'd rather they pop than a ribbon.
Josh,
Are you still working in the audio field? 

[josh358]

Yesterday I had a Winged "C" 6550 decide to go "Good-Bye Cruel World" and it made me think of this thread.  I know it's about resistors but fuses kind of crept in somewhere along the line.
At any rate, the fuse in the amp took the hit but I do find the fuses in the speakers comforting.  I'd rather they pop than a ribbon.
Josh,
Are you still working in the audio field?

But everyone knows he purpose of the ribbon is to protect the fuse.

Mostly retired now, although I'm getting kind of bored so I may go back to it (or pro video, which I actually ended up doing more of).

[kevin360]

I confess that I'm a conservative when it comes to speaker fuses, but that Hafler manual pretty much reinforces what I'd thought. I think I'd want to try it first, preferably in some kind of blind test, before I'd take the risk with my own speakers. It's not that I blow fuses these days, but accidents do happen.

That article had something to say about using fuses with higher ratings as well. I may be nuts, but I think that might be a possibility as long as the melting time of the fuse is commensurately reduced. Thus, the current through the fuse stays further from the fuse's melting point, but the fuse still protects the ribbons by virtue of its reduced reaction time – perhaps even better than the factory implementation. I dunno – seems possible. Listening without fuses is inspiring me to seek a better fusing solution.

Bass is like that isn't it? It seems like a foundation for the rest of the spectrum.

You sound like you are pretty happy with the remodel. You have that 'Got something accomplished' glow in your writing.

It's awesome to get deep, deep bass without any boominess anywhere higher. The problem is that there is just so much variation from recording to recording. Lowering the crossover point allows me to bring out what got tweezed down without over-emphasizing what was left alone. Yeah, I'm pretty excited. This is what I want but it would be neat to be able to control the levels from where I sit.

Yesterday I had a Winged "C" 6550 decide to go "Good-Bye Cruel World" and it made me think of this thread.  I know it's about resistors but fuses kind of crept in somewhere along the line.
At any rate, the fuse in the amp took the hit but I do find the fuses in the speakers comforting.  I'd rather they pop than a ribbon.
 

I have a KT88 suffering from a cold – well, it spits and sputters when it's cold. (Davey was right. The problem resurfaced – with consistency.) I pulled the amp and loaded it with speakers about which I couldn't care less and swapped tubes between channels and the problem moved (though it does cross into the other channel to some degree). I'm curious about other tubes – a set (8ea) of SED/Winged-C KT88-WCs would run $180 less than the set VAC sells (from an undisclosed Chinese manufacturer). I'll have to suffer with the Pass for a while. In fact, I've been thinking about keeping both – a solid (state) backup never hurts when you go with valves. 

By the way, I had to sit there and listen to the spit and sputter - twice - without fuses. Even though it sounded ugly, it didn't get too loud and it caused no harm, but it *had to go*. It's just one of those things you accept when choosing valves.

Anyway, I am interested in your assessment of the Winged-C - pre-meltdown. 

[josh358]

That article had something to say about using fuses with higher ratings as well. I may be nuts, but I think that might be a possibility as long as the melting time of the fuse is commensurately reduced. Thus, the current through the fuse stays further from the fuse's melting point, but the fuse still protects the ribbons by virtue of its reduced reaction time – perhaps even better than the factory implementation. I dunno – seems possible. Listening without fuses is inspiring me to seek a better fusing solution.

Actually, I was thinking along similar lines, not in terms of fuses (have you checked to see what they sell by way of fuses with non-standard characteristics), but when I was thinking of relay circuits. My thinking was that while the risk to a Mylar or dynamic tweeter is essentially from overheating, the main risk to a ribbon tweeter may be from excessive physical excursion because there are no adhesives or plastic to melt, just the aluminum itself, and that has plenty of exposure to the air. So, if that's true, you might be able to go with a very quick breaker that has a somewhat higher current limit.

But my inclination if it's still a real problem would still be to make an active circuit with a relay. That way, there's really nothing to muck up the sound. Hell, someone could bottle it and sell it as an overpriced accessory. Actually, I'm surprised no one has done this. I guess it's more profitable to sell $75 fuses that don't blow.*

*The legal department insists that I add "allegedly."

[SteveFord]

When I ran KT88s I used Ei from Yugoslavia which are NLA so you're SOL if one of yours is FUBARed, OK, typical SNAFU.
I switched to the Winged C 6550s which were pretty close but not as good. 
Over on the tubeophile circle there was a good thread on 6550s which you might want to check out.

[kevin360]

Yeah, I searched that circle last night for references to 'KT88'. I found some interesting discussions. There does seem to be some consensus on the Shunguang Black Treasure KT88-Z - generally regarded as a superb tube. Gee, $650 (if I decide to trust the factory over the importer) to completely re-tube the drive stage of my VAC - that's not bad (especially considering I saved $10K over new MSRP by purchasing one with a few years on it). The cool thing is that would essentially make it a brand new amp.

Comments about certain tubes corroborated what I'd read elsewhere - I know a few to avoid. I've read mixed reviews of others - liked the Winged-C. I've also read that the KT-88 will generally better the same brand of 6550, which means (if uniformly true) that your Winged-Cs started with a disadvantage.

This is both the upside and the downside of tubed gear.

[SteveFord]

It could be that KT88s are the better tube but VTL was pretty insistent that my amps came with 6550s and KT88s were not going to work out very well without resistor swapping and I should yank them out or (better yet) return the amplifiers to the factory for some major upgrades!
The best piece of advice that I can give you is to buy your tubes from someone with a solid return policy as defects will generally surface within the first week or three.
I use thetubestore up in Canadia land but there are plenty of others that are equally good.
And now, back to speaker resistors - sorry for the derailment.

[Emsquare]

Basically by accident. It was after college and I was happily sitting around doing nothing, so happily in fact that when my mother met a guy who ran a sound studio at a party and he mentioned that he was looking for someone she said "Hire my son!" So much for job fairs, eh? It was never like work. I mean, there was a lot of pressure and long hours, but basically it was lots of toys and million dollar budgets to spend on your hobby.

Well that didn't suck. Thanks Mom. We'll have to find interesting questions to ask you about your life in the studio. Like... What was your most memorable accomplishment(s)? Most interesting studio personality?

I confess that I'm a conservative when it comes to speaker fuses, but that Hafler manual pretty much reinforces what I'd thought. I think I'd want to try it first, preferably in some kind of blind test, before I'd take the risk with my own speakers. It's not that I blow fuses these days, but accidents do happen.

And why wouldn't you be? All I am looking to accomplish with this is to find out if there is anything to the notion of fuses having detrimental effects in audio equipment. Which I have been skeptical about to begin with. I needed something more than anecdotal reasons for specialty fuses. This mostly satisfies my curiosity on the subject. There is a limit to how much thought I'm putting into it for now. What I really want to be pondering is my next volume control system and not fusing. This is one less rock I am going to look under in the persuit of improvement. I don't know when the Hafler manual was written but there was a Stereophile review on that model in 1987. Thanks offered to the contributor at diyAudio for finding that.

It's awesome to get deep, deep bass without any boominess anywhere higher. The problem is that there is just so much variation from recording to recording. Lowering the crossover point allows me to bring out what got tweezed down without over-emphasizing what was left alone. Yeah, I'm pretty excited. This is what I want but it would be neat to be able to control the levels from where I sit.

I couldn't agree more Kevin. Given the choice why do without? Bass is FUN!

I have had a somewhat similar experience trying to get the superior bass I would like. Although what I have is pretty satisfying I believe there is room for improvement. I'm not really having the level match problem that you describe. I have had more of a perceived variance with bass definition. Some days it sounds just about perfect and other days there is a loss of vividness to it. And it is on the same tracks. This perplexes me a bit and I'm not sure how to address it. Since I forsee new subs in the future I'll focus on that another day.

[berni]

for finding that.

I couldn't agree more Kevin. Given the choice why do without? Bass is FUN!

I have had a somewhat similar experience trying to get the superior bass I would like. Although what I have is pretty satisfying I believe there is room for improvement. I'm not really having the level match problem that you describe. I have had more of a perceived variance with bass definition. Some days it sounds just about perfect and other days there is a loss of vividness to it. And it is on the same tracks. This perplexes me a bit and I'm not sure how to address it. Since I forsee new subs in the future I'll focus on that another day.

Funny , this is the same thing I also did noticed?!!

[SteveFord]

Bass perception seems to depend upon your mood - some days it's perfect, others days there's too much bass or too little.  Right now I'm futzing around with my preamp trying to get the bass just right - some .047 AuriCaps are in my near future.  I dunno, maybe I just like playing with a soldering station and swapping tubes around.
I know that the subject of bass and room response is of interest to Magnepan and they're tackling the subject by using two DMWs with good results
http://www.magnepan.com/DWM_and_DW_1_Woofers

or there's always Mr. Hsu
http://www.hsuresearch.com/index.html
who does the funniest thing: he'll go to a show with his subs and speakers, buy the absolute cheapest crap he can get at Best Buy to drive everything with and everyone always raves about the sound.
His trick is to use multiple subs.

[Davey]

There's a school of thought that if you get enough woofers in enough places you can excite every possible room mode there is and have beautifully "even" bass. 

Cheers,

Dave.

[berni]

I think it is more then just mood, something is happening..

[tberd]

 Why add to the signal path? If your music is bright and harsh get some tubes. Lots of em'.......

tberd