Something stirs in the Undergrowth

pre65 · Post by **pre65** » Tue Feb 03, 2015 12:10 pm

Kent men go to work on motorcycles.

Or, at least two on here do.

jack · Post by **jack** » Tue Feb 03, 2015 12:13 pm

I have to commute into Cannon Street - about 50 minutes each way from our little village. Man of Kent, me, not some lowly Kentish Man

Not normally a bad trip at all - nice, air-conditioned, bright, modern trains - lovely countryside. Nice & cosy...

Bet you froze your nads off this morning

pre65 · Post by **pre65** » Tue Feb 03, 2015 12:19 pm

nickds1 wrote:I have to commute into Cannon Street - about 50 minutes each way from our little village. Man of Kent, me, not some lowly Kentish Man

Not normally a bad trip at all - nice, air-conditioned, bright, modern trains - lovely countryside. Nice & cosy...

Bet you froze your nads off this morning

No me, I'm an Essex boy. I ride for pleasure only, but that can include green lanes in the depths of winter.

pre65 · Post by **pre65** » Tue Feb 03, 2015 12:48 pm

Back on topic, they look really good Mark.

Paul Barker · Post by **Paul Barker** » Tue Feb 03, 2015 2:37 pm

They assemble fish tanks with nothing more than clear silicon. But that is glass.

jack · Post by **jack** » Tue Feb 03, 2015 2:42 pm

Paul Barker wrote:They assemble fish tanks with nothing more than clear silicon. But that is glass.

...and its not about 1 inch thick - we have a Jewel fish tank with the black silicone sealant corners, but in all honesty its not that attractive and the glass is only about 4mm thick...

Those speakers look absolutely F.A.B. I hate to think what the machines acrylic cost

steve s · Post by **steve s** » Tue Feb 03, 2015 6:16 pm

impressive mark, they look very good , I hope they work out for you

my diy has got progressively worse over the last few years as I realise nothing I make is ever permanent enough to warrant doing too good a job.

but hopefully yours looking as good as that, will be much more permanent

IslandPink · Post by **IslandPink** » Tue Feb 03, 2015 6:44 pm

Steve - your stuff is always well-enough made and impressive considering how quickly you work . I was particularly impressed with your new amps at the last Owston - very original .

Nick - the cost of the two perspex front panels ( 1000mmx460mmx20mm ) with two accurate speaker cut-outs in each, including the packing and courier to North Wales, was £250 .

Well, here below another two pics :
(i) Daylight shot of unit no.1 - shows it a bit better
(ii) Fwoarr ! - chokes have arrived !

Paul Barker · Post by **Paul Barker** » Tue Feb 03, 2015 8:10 pm

Phuaaarrrr

IslandPink · Post by **IslandPink** » Fri Feb 06, 2015 9:43 pm

Having a listen now with crossover as per page 95, except the choke is 8.2mH and I've gone for about 135uF cap .
There's been a fair bit of Brand X and King Crimson so far

Waiting for a mountain of capacitors to run in. Lots to enjoy. The house 'Quasar ' sound is there . Dynamics are great , bass articulation really good. Tone is good, but not quite there. The 208Ez has the expected slight harshness on vocal and a bit bright. The overall presentaion is a bit bright and lean, so I think I might reduce the 3.3R on the Supravox with 1.5R . I can clip-lead it out first, to get a feel for the changes. More running-in required for now though .

Ali Tait · Post by **Ali Tait** » Sat Feb 07, 2015 12:31 am

Cor!

Enjoy..

simon · Post by **simon** » Sat Feb 07, 2015 2:01 pm

Looking good Mark. Very interested to see how they compare to mine.

Are the 208s new? Mine did improve quite a bit as they ran in, but it was 10 years ago now and I just don't remember how they changed

.

IslandPink · Post by **IslandPink** » Sun Feb 08, 2015 11:28 am

They're new-ish, but both have been used a bit on the open-baffle experiments . I think this unit has been used less. The Supravox from Steve is also lightly used .
I need to install some socket nuts on the upper baffle section and fit a temporary piece of wood there, it will slightly improve the bass extension.
I now need to look more at the option for a 4kHz notch filter inside the amp , as I mentioned before ( to take the edge off the Fostex peak ) .

IslandPink · Post by **IslandPink** » Sun Feb 08, 2015 7:40 pm

Two updates :
(i) taking off the 3.3R on the Supravox sounds better. Obviously theory and practice for the crossover are different on this combo . Simon - have you run these two drivers yet ?
(ii) I tried messing about with LT Spice making a RCL notch filter inside a 4P1L/300B amp and didn't get very far. Welcome to the next level ? ( Nick -

any ideas ? ) .

The Fostex is too aggressive on vocals ( as expected from previous lash-ups ) and will need something .. but in my case an 800Hz low-pass may be enough to tame the 4kHz area without a notch, anyway ( long-term ) .

Post by **Nick** » Sun Feb 08, 2015 9:03 pm

IslandPink wrote: (ii) I tried messing about with LT Spice making a RCL notch filter inside a 4P1L/300B amp and didn't get very far. Welcome to the next level ? ( Nick - any ideas ? ) .

Not sure, but sounds like its not worth a lot of complexity if the horn is going to take over that area anyway,

But this link might help

http://sim.okawa-denshi.jp/en/RLCbekeisan.htm

audio-talk

Something stirs in the Undergrowth

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