Bottlehead Forum
Bottlehead Kits => Legacy Kit Products => Topic started by: paulw on May 06, 2010, 02:34:46 PM
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So after many months of procrastination I finally bought and installed some BH-5 nickel/steel outputs, BH-6 chokes and some 10uf Clarity caps (had already changed the 0.1uf's). I have to say that the first time I listened to the Paramours after the upgrade I was really wondering why! Whilst the mid-band is
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I have never yet managed to enjoy the sound of a "new" amp, i.e. one with new transformers or capacitors. Often they get worse over the first 10-20 hours. It will take at least 50 hours of music before you can make a valid judgment, if your ears are like mine. Some caps - teflon in particular - take hundreds of hours.
I usually put a fat 20-watt, 8 ohm resistor across the output instead of the speaker - so I don't have to listen to the nasty noise - and run the amp fairly hard. New tubes seem to wake up without music, but not capacitors and certainly not transformers or signal chokes. It's this experience - burning in without listening - that convinced me the effect was real and not just getting used to the sound, as some maintain.
While you are not listening to the break-in process, you can search the archives if you like - you'll find plenty of posts on the subject.
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I can't comment on your particular situation, but I will say I experience the same thing every time I change signal-path capacitors larger than about a microFarad in anything. The new ones sound so dreadful that I eventually convince myself that they need to come out!
Fortunately, about that same time they seem to run in and sound fabulous. I can't begin to put a figure on how much time is enough time, and I have even had them sound great at first, then go through a phase where they really sound awful on their way to breaking in. Makes me second-guess my choices, but I have yet to actually un-do any upgrade I've ever done.
So, my suggestion is to play it, even if you have to leave the room! I will be very much surprised if you end up not liking the upgrades very much after a while.
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Thanks for te quick responses - say's he with a sense of relief :
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Paul,
If you don't want that iron I'll swap with you. Seriously, I put in similar upgrades in my Paramours, but no nickel. What I immediately heard was a fleshing out of the images, they produced body. The rest took time to come in but in the mean time I was mesmerized with the improved fleshing out of the images.
But poster Chacodude (lives across the street from my in-laws), had loaned me come Clarity caps and they did not appeal to me. I'm betting you have tried them enough that you know you do like them. Just asking. I opted for the Obbligato PP Film in oil 10uF.
I like PJ's suggestion that you burn the iron in, in place with a resistor. I do the same with capacitors. Iron has something called hysteresis which has to be established. So the big resistor is a great idea. That should "set" the iron and capacitor.
JC, I often post this link to instructions, with a picture to show the wiring, on how to break in caps before putting them into the circuit:
Fast Break In Post Link (http://www.bottlehead.com/smf/index.php/topic,80.msg286.html#msg286)
It gets you past the awful stage and gives 90% of the end sound. I use the GainClone in my shop system. I don't waste tubes for that.
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My experience with the same upgrade is almost the same, except I started with a Solen cap....mushy bass and hissy highs. After a few weeks, I replaced the cap with a Mundorf Supreme. The Mundorf went through a weird series of changes for a week or so, and then things settled in. Plenty of bass extension, but still not quite as "quick" as before, and smooth and relaxed through the mids and highs. Overall, I like the change, but if I was running the amp with restricted lows, as in a "sexy speaker" set-up, I might be tempted to put the old upgrade trans. back in. The pluck of bass strings is a little less distinct.
Bernie
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Bernie,
There is a leap in price between the Solen and Mundorf caps. But a meaningful difference. The Obbligato caps are a great bang for the buck but don't compare with Mundorfs. A pair of Silver/Oil for my Paramours would run $272.36 + shipping.
Don't get me wrong, I am impressed with the sophisticated sound of the Mundorf Silver/Oil in my FP 2. Money well spent!
Maybe for my birthday and Christmas combined?
Paul,
It has been my experience that the better the cap the worse it sounds at first and the longer it takes for them to sound the best. Teflon signal caps take 200 hours. That is why now I don't even put in an upgraded power supply cap without burning them in.
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....But poster Chacodude (lives across the street from my in-laws), had loaned me come Clarity caps and they did not appeal to me. I'm betting you have tried them enough that you know you do like them. Just asking. I opted for the Obbligato PP Film in oil 10uF.
I like PJ's suggestion that you burn the iron in, in place with a resistor. I do the same with capacitors. Iron has something called hysteresis which has to be established. So the big resistor is a great idea. That should "set" the iron and capacitor.
JC, I often post this link to instructions, with a picture to show the wiring, on how to break in caps before putting them into the circuit:
Fast Break In Post Link (http://www.bottlehead.com/smf/index.php/topic,80.msg286.html#msg286)
It gets you past the awful stage and gives 90% of the end sound. I use the GainClone in my shop system. I don't waste tubes for that.
Hi Grainger, actually I have no experience of differing caps so just went for the basic ones listed on the Hi-Fi Collective site, that really was the total extent of my research! Not too sure I could really be 'that' bothered to optimise these by a process of trial and error - especially if we are considering a 50-100hr burn-in period to see if I like the result, life's too short ;
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Bernie,
That is a leap in price between the Solen and Mundorf caps. But a meaningful difference. The Obbligato caps are a great bang for the buck but don't compare with Mundorfs. A pair of Silver/Oil for my Paramours would run $272.36 + shipping.
Don't get me wrong, I am impressed with the sophistication of the Mundorf Silver/Oil in my FP 2. Money well spent!
Hi Grainger
Silver/oil I wish! The "regular" supremes were about $40 each back when I bought them. I've had better luck with Clarity caps than Solens in the places I've had them.
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Yes, not to mention that Doc hates "what cap" threads. I'll post a link to the Obbligato caps below. You have the burn in post now, and I strongly urge you to read and try that. It suggests burning in with your music at a high but reasonable volume. It doesn't use odd tones or anything, just music. So I would consider it a soft over time break in not a hard one. The benefit is that it is continuous. Then only difference is not turning it off and on to continue. In your case you need iron burn in so use your Paramours. 100 hours is just over 4 days continuous.
If I had a plausible 10uF cap at 600+ volts I would send them to you for trial, but I don't. And your iron is excellent, nicer than mine. I guess the best advice I can give is a repeat of Paul Joppa's, get a 20W 8-10 ohm resistor (four 10 ohm 10W resistors in series parallel from Radio Shack gets this) and run the amp with music. If you feel safer, do it only when you are at home. But both the iron and caps need burn in. I don't disagree with Mike at MQ except on this point, his iron is amazing!
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Hi Grainger
Silver/oil I wish! The "regular" supremes were about $40 each back when I bought them. I've had better luck with Clarity caps than Solens in the places I've had them.
Aha! Yes, Solens are an upgrade in sound from the Brown stock caps and I understand Clarity caps are an upgrade from Solens. Many PP film (Auricaps, Hoveland, Mundorf) are better than Solens, in my opinion, to my ears, etc.
But sadly, maybe not sadly, everyone likes a different cap. Everybody wants to hear something different. And because of that I agree with Doc, the what is the best cap threads aren't really helpful. "Paully" wants the lowest distortion possible, I want to hear a well defined soundstage and clean highs. And we all hear things differently. I have found in the last 30 years that there are many of my friends who never hear any depth in a stereo. Everything to them comes from a line defined by the speakers. Psycho-acoustics explains a lot of this.
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I would have to throw in a quiet post of agreement that it wouldn't hurt anything to swap out the clarity caps.
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I would have to throw in a quiet post of agreement that it wouldn't hurt anything to swap out the clarity caps.
Well I had to take a punt at something and these were it! However, I might try out a pair of Obbligato film caps just to see - but that would really be it.
paul
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These are polypropylene film in oil. I neglected to insert the link. Here it is:
http://www.diyhifisupply.com/catalog/35
They cost $11 each and there is an additional shipping cost that has to be selected. I don't see it on this page. Possibly it is at checkout now. But don't let the cost fool you, these are sweet, smooth and give clean highs.
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In re-reading this thread, I thought of another thing. The BH-5 Magnequest transformer has some teflon in it, in places that are sonically significant. It may take longer to break in fully than a more old-fashioned design. I'd expect the difference if any to be more in the very high frequencies, but of course how these subtle things manifest subjectively is sometimes surprising!
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In re-reading this thread, I thought of another thing. The BH-5 Magnequest transformer has some teflon in it, in places that are sonically significant. It may take longer to break in fully than a more old-fashioned design. I'd expect the difference if any to be more in the very high frequencies, but of course how these subtle things manifest subjectively is sometimes surprising!
Yes, I got that point from trawling through the archives - just sitting tight playing music and movies for now & waiting for some extra MagneQuest magic to arrive - as I'm sure it will ;
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Well the MagneQuest magic has indeed arrived - the upgrade is worth every penny. However (there always is a 'however' isn't there) bass output is considerably more articulate and seemingly deeper and this is giving me a bit of a problem as I'm perhaps 'overspeakered' for my rather small room with three way corner horns rated at 102db/w with 15 inch bass units. The better bass is coupling with the room a bit to well! Would there be any mileage in altering the value of the Parafeed capacitor (higher/lower?) to reduce low frequency output?
Paul
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Could be. The speaker impedance fluctuates quite a bit in the deepest bass for most speaker designs, and this can interact with the parafeed capacitor. It's different for every speaker, so there's no reliable way to predict the effect. I'd try something smaller - start with the old 3.3uF, then maybe 5-6uF (you could parallel the two 3.3uF and listen in mono perhaps) to compare with the 10uF; that should give you an idea of what the effects will be. It's possible but (IMHO) unlikely that a larger capacitor will have much audible effect.
You may of course just be hearing the effect of the corner location, combined with the SET's moderate damping factor - room acoustics are always difficult!
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You can indeed lower the parafeed cap to induce a bit of rolloff.
It's easier to lower the value of the coupling cap (cheaper cap with less voltage across it).
The formula is C=1/(2*R*Pi*F) where R is the grid leak resistor in ohms (249000) and F is the -3db rolloff point. This will give you a C value in farads.
PJ would have good ideas on values to try, but I would suggest trying coupling caps that move the frequency up 10hz at a time until you find what you like.
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Bear in mind that you can create a bit of a hump in the bass response just above the roll off point if you shrink the cap size too much. If that hits right where your bass boom is it could get worse instead of better. I'd consider reducing the cap size as a last resort and try getting the speaker to work with the room as well as possible first.
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Bear in mind that you can create a bit of a hump in the bass response just above the roll off point if you shrink the cap size too much. If that hits right where your bass boom is it could get worse instead of better. I'd consider reducing the cap size as a last resort and try getting the speaker to work with the room as well as possible first.
Yes, basically reading the above posts it would seem that further passive bass traps will be the order of the day as I feel (given my room dimensions) that a cap value change may be toying with the response below my problem area - I'll try and plot it this evening. The impedance curve of the speakers seems reasonably benign with a minimum of 5ohms and a max of 9ohms from 10 to 500Hz (impedance curve supplied by the speaker designer) and nothing over 13.5ohms at all.
Paul
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Doing some 'quick and dirty' measurements from the listening position with a basic SPL meter I would appear to have a significant 'hump' in output from 85-105Hz with the peak at 96Hz.
Paul
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To know if any of that hump is due to the amp's frequency response you really need to measure the response of the amp into the same load that your speakers show it. It is most likely that the hump you are seeing is a composite of several room modes with the one at 96Hz being the worst. The place to start is to move your speakers a foot or two and see if the hump changes
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Are the Pi Corner Horns like Klipsch Jubilees, with a side built into them? That is, the Jubilees do not need the corner to function.
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Are the Pi Corner Horns like Klipsch Jubilees, with a side built into them? That is, the Jubilees do not need the corner to function.
The room corner is integral to the design, this actually forming part of the bass horn. The main reason I went for these was that fitting tight into the corners they take up less virtual floor space than my mini-monitors which like to be 3 foot into the room. No I've come to the conclusion it's going to have to be more passive trapping but targeted at the mid 90's specifically.
Paul