Something stirs in the Undergrowth
- IslandPink
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#272 Phew !
Phew !
The second piece of bendy MDF was easier .
I feel quite righteous now
The second piece of bendy MDF was easier .
I feel quite righteous now
"Once you find out ... the Circumstances ; then you can go out"
- IslandPink
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#274
Actually Colin I'm not too bothered about that job . Might be quite relaxing , I'll pick a nice sunny day on the back porch .
The fitting of those MDF sides was a stressful job . With the glue going off in about 15mins , banging in little veneer pins every 2-3 inches and trying to get the piece from veering off ( I cut it a bit too close to the min size ) - was getting quite a sweat on there . You have to keep checking it's fitting tightly along the ply all the way ; and wipe off drips of glue running down ; and avoid standing on the glue bottle ( thankfully not THIS time ! ) .
The fitting of those MDF sides was a stressful job . With the glue going off in about 15mins , banging in little veneer pins every 2-3 inches and trying to get the piece from veering off ( I cut it a bit too close to the min size ) - was getting quite a sweat on there . You have to keep checking it's fitting tightly along the ply all the way ; and wipe off drips of glue running down ; and avoid standing on the glue bottle ( thankfully not THIS time ! ) .
"Once you find out ... the Circumstances ; then you can go out"
- IslandPink
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#275 Filler
Back on the job after a week in the Lakes.
Looks like 500g of filler doesn't go very far. Looks like I should have bought about 3kG !
Looks like 500g of filler doesn't go very far. Looks like I should have bought about 3kG !
"Once you find out ... the Circumstances ; then you can go out"
- IslandPink
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#276 Flange
Slow progress ... dividing time between this and Pass F4 amp finishing .
Here is a 'simulation' picture before the rear flange is fitted ; with B&C speaker also plonked on top . I like it !
Plenty to do yet on the second layer of 9mm bendy and subsequent filling .
Here is a 'simulation' picture before the rear flange is fitted ; with B&C speaker also plonked on top . I like it !
Plenty to do yet on the second layer of 9mm bendy and subsequent filling .
"Once you find out ... the Circumstances ; then you can go out"
- Paul Barker
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#277
Excellent, looking forward to hearing it.
- IslandPink
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#278 Fane & Bud
Not too far from getting one side going .
New batch of Fane Studio 8M nearly ready :
http://www.diyaudio.com/forums/group-bu ... run-9.html
I've also been e-mailing Bud Purvine and he's finalising the design of two pairs of 2A3/6B4G output transformers.
Probably level 1 construction and M3 lams for 120-700 Hz band ( with good performance eg. 2 octaves each side ).
The pair for the 288H's ( 700Hz-8k) are likely to be level 3 construction with litz secondaries and again M3 lams . Could be 48% nickel , not sure yet.
Shame these things are not going to be portable for Owston-type meets . Also the amps and speakers are going to be inseperable !
ILPS
New batch of Fane Studio 8M nearly ready :
http://www.diyaudio.com/forums/group-bu ... run-9.html
I've also been e-mailing Bud Purvine and he's finalising the design of two pairs of 2A3/6B4G output transformers.
Probably level 1 construction and M3 lams for 120-700 Hz band ( with good performance eg. 2 octaves each side ).
The pair for the 288H's ( 700Hz-8k) are likely to be level 3 construction with litz secondaries and again M3 lams . Could be 48% nickel , not sure yet.
Shame these things are not going to be portable for Owston-type meets . Also the amps and speakers are going to be inseperable !
ILPS
"Once you find out ... the Circumstances ; then you can go out"
- IslandPink
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#280 Interesting Calculation
It's a sign Mike ! -
A sign that I have a sore arm and the house fills with dust every time I open the door !
Colin was right, it's a chore doing that filling. I spent far too much time getting the first layer really nice - it'll only get covered up with the second layer . Won't be so picky on the second speaker .
Meanwhile...
James D did a calc for me today on e-mail :
Q : How much power do I need from each small SE amp ( there are three to power the three horns ) , to get 90dB average at the listening position ?
A : 30mW
A sign that I have a sore arm and the house fills with dust every time I open the door !
Colin was right, it's a chore doing that filling. I spent far too much time getting the first layer really nice - it'll only get covered up with the second layer . Won't be so picky on the second speaker .
Meanwhile...
James D did a calc for me today on e-mail :
Q : How much power do I need from each small SE amp ( there are three to power the three horns ) , to get 90dB average at the listening position ?
A : 30mW
"Once you find out ... the Circumstances ; then you can go out"
- Dave the bass
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#282 Re: Interesting Calculation
Um. Having heard the effect SE amps can have on bass (high output impedance interacting with speaker impedance peaks), I'd consider trying them with a SS amplifier too. You might find you prefer the sound with the SE amps, but horn resp only considers a voltage source driving the speakers. A non-zero output impedance may not give the same results as the sims.IslandPink wrote:...
Meanwhile...
James D did a calc for me today on e-mail :
Q : How much power do I need from each small SE amp ( there are three to power the three horns ) , to get 90dB average at the listening position ?
A : 30mW
Chris
- IslandPink
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#284 Amps ( or lack of )
Come on guys ...
Why the ...'k would I want to run highly efficient horn speakers from SS amps ? I mean the whole point of doing this thing was to be able to run 2A3 or 45 type amps to get the lowest distortion and highest audio quality !!
The only SS option I might ever consider is driving low bass and bass/mid from the Passlabs F4 . With any other SS amps you are literally 'down in the noise' at this sort of output .
As regards the driving impedance, you'll see if you look at the Hornresp data for the bass/mid horn I've used about 1.8R on all the sims . The bass/mid horn is not as picky about driving impedance as the Tapped horn , in that case as Chris pointed out, you need the lower impedance, and 0.3R from Pass F4 + cables should be ideal .
Anyway, what about the 'optimum' driving impedance for critical damping ? - it does not have to be as low as possible . I refer you to a recent post on JJ's blog for a reminder on that one :
http://hifiheroin.blogspot.com/2011/03/ ... dance.html
Rant over, I think
MJ
Why the ...'k would I want to run highly efficient horn speakers from SS amps ? I mean the whole point of doing this thing was to be able to run 2A3 or 45 type amps to get the lowest distortion and highest audio quality !!
The only SS option I might ever consider is driving low bass and bass/mid from the Passlabs F4 . With any other SS amps you are literally 'down in the noise' at this sort of output .
As regards the driving impedance, you'll see if you look at the Hornresp data for the bass/mid horn I've used about 1.8R on all the sims . The bass/mid horn is not as picky about driving impedance as the Tapped horn , in that case as Chris pointed out, you need the lower impedance, and 0.3R from Pass F4 + cables should be ideal .
Anyway, what about the 'optimum' driving impedance for critical damping ? - it does not have to be as low as possible . I refer you to a recent post on JJ's blog for a reminder on that one :
http://hifiheroin.blogspot.com/2011/03/ ... dance.html
Rant over, I think
MJ
"Once you find out ... the Circumstances ; then you can go out"
#285
chill bro...the young one has more time to learn than the rest of us...and at the moment he dances to a different tune.....
from an audio point of view I wish I'd known what he knows when I was that age.....however, on reflection I wouldn't jeopardise any of the experiences I have had since then..so maybe I'll leave well alone
snigger
from an audio point of view I wish I'd known what he knows when I was that age.....however, on reflection I wouldn't jeopardise any of the experiences I have had since then..so maybe I'll leave well alone
snigger
There's nowhere you can be that isn't where you're meant to be