I've just finished this circuit! Wow! I didn't expect such a huge effect!
Even on-axis, B200 doesn't shout. In fact, for the first two minutes, it sounded dull
Now my ears have adjusted and it sounds more normal, though I miss a bit of "tizzzz".
I am using it between a tube buffer and a Pass Zen variation 9 amp -without feedback, and input impedance adjusted to about 100k.
I'll do more listening and see it I prefer this sound over longer periods. It sounds much easier, somehow "lighter". Sound floats in the air. As I listen, I hear a peak in the bass that I didn't notice before....
Anyway, this circuit is well worth trying. Maybe I will have to play with some values until I get exactly the sound I want.
Thanks a lot,
Vix
Even on-axis, B200 doesn't shout. In fact, for the first two minutes, it sounded dull
Now my ears have adjusted and it sounds more normal, though I miss a bit of "tizzzz". I am using it between a tube buffer and a Pass Zen variation 9 amp -without feedback, and input impedance adjusted to about 100k.
I'll do more listening and see it I prefer this sound over longer periods. It sounds much easier, somehow "lighter". Sound floats in the air. As I listen, I hear a peak in the bass that I didn't notice before....
Anyway, this circuit is well worth trying. Maybe I will have to play with some values until I get exactly the sound I want.
Thanks a lot,
Vix
Hi Vix, You're welcome. The "tizzz" will probably come back, hopefully in a more natural way. At present you are hearing things the tizzz was masking, and your attention is focused on the new sounds, like the peak in the bass.
If you change values to suit your taste, change only one at a time, and wait till you have adjusted to the sound before judging the change.
I guess you'll have to hunt down the bass peak. That can be fun. Try disconnecting the bass helpers, it could be as simple as too much overlap on the bass roll-off.
Thanks for the feedback. It will be interesting to see what others have to say, and then fine tune the circuit.
Regards,
Geoff.
If you change values to suit your taste, change only one at a time, and wait till you have adjusted to the sound before judging the change.
I guess you'll have to hunt down the bass peak. That can be fun. Try disconnecting the bass helpers, it could be as simple as too much overlap on the bass roll-off.
Thanks for the feedback. It will be interesting to see what others have to say, and then fine tune the circuit.
Regards,
Geoff.
Hi,
Geoff, thank you for providing such a nice circuit. While I know that cutting the dustcap and installing a phase plug would be the best option, I was a bit reluctant to do it and was looking for some reversible mods.
After a bit more listening, I am much happier with B200’s than before applying a PLL.
Overall, it sounds “quieter” and less aggressive. Bass peak was solved by lowering the gain on a bass amp. (it is biamped-second amp driving a pair of 12”) I had upped the bass to match a screamy midrange. It was sounding more like a PA, less hi-fi. Sometimes I enjoyed it, but couldn’t listen for very long. Now that there are no nasty peaks, they are much easier to listen, fatigue-free.
On the negative side, they sound a bit soft and just occasionally I miss that shout.
Still, I am going to leave them as they are, and just enjoy for a while.
Regards,
Vix
Geoff, thank you for providing such a nice circuit. While I know that cutting the dustcap and installing a phase plug would be the best option, I was a bit reluctant to do it and was looking for some reversible mods.
After a bit more listening, I am much happier with B200’s than before applying a PLL.
Overall, it sounds “quieter” and less aggressive. Bass peak was solved by lowering the gain on a bass amp. (it is biamped-second amp driving a pair of 12”) I had upped the bass to match a screamy midrange. It was sounding more like a PA, less hi-fi. Sometimes I enjoyed it, but couldn’t listen for very long. Now that there are no nasty peaks, they are much easier to listen, fatigue-free.
On the negative side, they sound a bit soft and just occasionally I miss that shout.
Still, I am going to leave them as they are, and just enjoy for a while.
Regards,
Vix
I installed a 27 tube pre ahead of Geoff's circuit & also have a 150HZ .01uf HP in the circuit also, cleans the mids up. I also bi-amp. With a good pre, this circuit is outstanding. If you think you are missing anything on top, just install a rear fire tweeter. I installed a ribbon in rear fire mode only @ 10k 1st order. Far superior to front fire in my system. My circuit did burn in,, only took a couple hrs. & I really hope others try the LL circuit out. For the money it is definatelly worth soldering it together. I have'n't even installed mine in a proper box, it is all hanging on input of amp. I am using the 180pf- .0027uf -220pf combo w/ SM's & rat shack carbon films. I have Bradley CC's but have not felt the need to even use them. It is nice when something works as this. I do not think Phase plugs can do what this circuit does, I have installed them before on FR's, the would help with beam, but the circuit address's something entirely differant. Not saying phase plugs wouldn't be a good bet, but I dought results would be the same. Both plugs & this circuit together I imagine would be very nice, but cap surgery in not for every one.
Thanks for the praise Joe. You're probably right in saying plugs won't do what the circuit does. The circuit wont do what plugs will either.
If you were to put on plugs, (and I suggest you do) the circuit may not be needed. It would at least need adjustment.
I have been experimenting with plugs on some little 61/2" w/r to the point I have a feel for shapes etc.
Anyone that has put up with my ranting and raving about my Wharfies will know I wouldn't cut them without being confident.
They are now sporting plugs. And I'm not sorry I cut the dome! There is no electronic trick up my sleeves that will do what the plugs do.
Geoff.
If you were to put on plugs, (and I suggest you do) the circuit may not be needed. It would at least need adjustment.
I have been experimenting with plugs on some little 61/2" w/r to the point I have a feel for shapes etc.
Anyone that has put up with my ranting and raving about my Wharfies will know I wouldn't cut them without being confident.
They are now sporting plugs. And I'm not sorry I cut the dome! There is no electronic trick up my sleeves that will do what the plugs do.
Geoff.
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Zen, your jealous again, just coz my whizzers are bigger than yours.
100 mm, and the motor's big enough to shake it.
I need to trim the ridge left from the dome, and replace the foam damper, it's a bit brittle.
Besides that, beauty 'round here is in the ear of the beholder.
100 mm, and the motor's big enough to shake it.
I need to trim the ridge left from the dome, and replace the foam damper, it's a bit brittle.
Besides that, beauty 'round here is in the ear of the beholder.
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Oh I'm getting the courage to try Dust cap surgery again..at least on maybe my Calrads,, but until I feel the need , the B200's stay as is..going back to active triode pre with this set up has me tickled. I love vintage driver's How did you muster the .........to cut those Wharfdales.....? Maybe I will try my Calrads..mmmmmmm scary...
Geoff H said:
I am standin up!!! U've bin peepin!
Seriously tho Geoff. With the sensitivity of the B200, your LL filter and a bit of encouragement, the tweaky boys with their 10watt tri-paths would kill for this down on the Class D pages.
Without knowing it, you've probably made their day (and another thread starts! Aaaahhh!)
Hi Joe, on hearing what I got out of the little 6n a halfers, with cone treatment to get the top end up (they were x-oed over to 2" tweeters originally) and then hearing the difference with the plugs, it was pretty easy. Mind you, these Wharfedales are far from stock. So it wasn't a case of destroying history (we did that 30 years ago!)
I was going to have some more practise on lesser gear, but thought what the heck. Cutting the large dome was easier than the little caps.
As it was, the Wharfies had a long cavity in the voice coil that needed filling. About 1.25" from the apex back to the pole piece. That's like a 1/4 wave trap at 2.7 Khz.
Regards,
Geoff.
I was going to have some more practise on lesser gear, but thought what the heck. Cutting the large dome was easier than the little caps.
As it was, the Wharfies had a long cavity in the voice coil that needed filling. About 1.25" from the apex back to the pole piece. That's like a 1/4 wave trap at 2.7 Khz.
Regards,
Geoff.
Geoff H said:
,yes.......I'm glad for ya.......so you have something on what I can be jealous 
look this-another pair........besides dirt and messed flexies,they're in perfect shape.......
little dammar,PVA and Mamboni+BudP............heaven is near
btw-I agree with ya that only toobz are good enough for this type of spks..........talkin' of SS - mebbe just xconductance amps
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The plugs aren't that hard to make. If you have a variable speed drill, a drill press and vice, vernier callipers, and a Philips bit, and dowel stock, you can DIY.
If you have never cut a dome, I suggest you get hold of some old drivers to play with. Smokehouse Bob said he had more control with a saftey razor than a scalpel type knife. That works for me to. Also, if you haven't checked out Dave's site,(Planet10) head there now.
On the Panasonics, the cap was glued to the VC former. I don't know if that's the case with the B200. Do not cut the former. I left a small ridge of the cap. Painted it with PVA, to harden it, then used sandpaper to smooth it down, then sealed it again. Be very careful not to let any dust into the gap.
Cut a length of dowel taking into account the distance from the apex to the centre pole, and the length you want protruding, square up one end, drill a pilot hole as close to the centre as you can. I used a washer as a guide. Fit a Philips head counter sunk screw.
Now we can turn the dowel with a screw driver, or the power drill with a bit. But first get the the diameter of the plug down to size. What we want is as small a clearance between the VC former and plug. I achieved 1/2 a mm. Then shape the plug on a sanding wheel, and finish by spinning the plug on the drill, cupping sandpaper around the plug end.
Dave uses 2 screws to hold the plug. My single screw hasn't moved on the Wharfedales (Oh! I've tried, the duelling percussionists on Sacred Fire) By countersinking the screw just below the surface, the base of the plug will have more grip than just the screw head.
This is what I started with.
If you have never cut a dome, I suggest you get hold of some old drivers to play with. Smokehouse Bob said he had more control with a saftey razor than a scalpel type knife. That works for me to. Also, if you haven't checked out Dave's site,(Planet10) head there now.
On the Panasonics, the cap was glued to the VC former. I don't know if that's the case with the B200. Do not cut the former. I left a small ridge of the cap. Painted it with PVA, to harden it, then used sandpaper to smooth it down, then sealed it again. Be very careful not to let any dust into the gap.
Cut a length of dowel taking into account the distance from the apex to the centre pole, and the length you want protruding, square up one end, drill a pilot hole as close to the centre as you can. I used a washer as a guide. Fit a Philips head counter sunk screw.
Now we can turn the dowel with a screw driver, or the power drill with a bit. But first get the the diameter of the plug down to size. What we want is as small a clearance between the VC former and plug. I achieved 1/2 a mm. Then shape the plug on a sanding wheel, and finish by spinning the plug on the drill, cupping sandpaper around the plug end.
Dave uses 2 screws to hold the plug. My single screw hasn't moved on the Wharfedales (Oh! I've tried, the duelling percussionists on Sacred Fire) By countersinking the screw just below the surface, the base of the plug will have more grip than just the screw head.
This is what I started with.
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Hi Guys, have a look here if you haven't yet:
http://www.diyaudio.com/forums/showthread.php?postid=1186757#post1186757
http://www.diyaudio.com/forums/showthread.php?postid=1186757#post1186757
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