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by steve s
Sat May 23, 2020 11:09 am
Forum: Assorted Stuff
Topic: Owston 2020
Replies: 32
Views: 2170

Re: Owston 2020

If it wasn't for this lockdwn, I'd probably not have the amps I've built these last few months... So I'd have been bringing the Px25 and a 2030 chip amp.. As it is I would have brought the 1.1 watt p650 based amp and the mofo.. and I would be scrabbling around to get the mofo looking respectable thi...
by steve s
Sat May 23, 2020 12:14 am
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415357

Re: Something stirs in the Undergrowth

IslandPink wrote:
Fri May 22, 2020 7:36 pm
steve s wrote:
Thu May 21, 2020 11:32 pm
12 '
At 25Hz , yes, 1/4 wave ie. 90° phase lag would be 11.3 feet to be pedantic - was that the calc ?
Yea.... Got there...
by steve s
Fri May 22, 2020 9:33 am
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415357

Re: Something stirs in the Undergrowth

With regard to the horn, with a folded horn the sound would have to still travel the 12 ' to get out of the horn giving the same time delay ? The problem is the relative time delay for different frequency sounds. When the horn is doing its job, you don't have that. It's like 100Hz waves and 1000Hz ...
by steve s
Fri May 22, 2020 9:25 am
Forum: Everyones Projects
Topic: Mofo
Replies: 51
Views: 893

Re: Mofo

Thanks gents, Ed I'll check the connections, but it's a strange one I have some spares for p1 I'll change it it happens a again
Ray I've spent another 2 hours reading that thread this morning... Its taking over my life... again il see if it reoccurs
Thanks both
by steve s
Thu May 21, 2020 11:32 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415357

Re: Something stirs in the Undergrowth

With regard to the horn, with a folded horn the sound would have to still travel the 12 ' to get out of the horn giving the same time delay ? Regarding open baffle and tone I completely agree I've implemented mine using a low order crossover and using more surface area. Along with the semi open baff...
by steve s
Thu May 21, 2020 9:16 pm
Forum: Everyones Projects
Topic: Mofo
Replies: 51
Views: 893

Re: Mofo

1st issue tonight.. The crackling came back so I was busy checking through the amp again Carefully moving/rocking the valves as I've doubts about the contacts. It's usually the centre pin on b5s. I'd turned the amp on and off 3 times over 10mins or so. The 3rd time there was a pulsing from one speak...
by steve s
Thu May 21, 2020 8:55 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415357

Re: Something stirs in the Undergrowth

I agree. Thats made me think.. So if I understand that correctly mark A horn bass speaker 12' long would have similar phase shifts as a 'flat' bass driver at 25 hz The type of speakers I prefer I know have a rising response, but also have less phase shift. Or lag behind the music less.. which could ...
by steve s
Thu May 21, 2020 12:03 pm
Forum: Everyones Projects
Topic: Mofo
Replies: 51
Views: 893

Re: Mofo

No problem Steve, it's good to see the progress you've made and you're clearly pleased with the results. One interesting aspect of the power supplies I linked to is that they used switched mosfet rectification instead of conventional rectifiers - gets good reports. Thanks ray it seems they do every...
by steve s
Thu May 21, 2020 9:08 am
Forum: Everyones Projects
Topic: Mofo
Replies: 51
Views: 893

Re: Mofo

Thanks ray, Mike has reported similar improvements with power supplies, I'll look into them, I'm using a fair bit of capacitance after the 'bricks', I measured the ripple and it seemed lowish, but I can't remember what is was, i'll check again. I'm sure there's room in the chassis to fit my own buil...
by steve s
Wed May 20, 2020 11:08 pm
Forum: Everyones Projects
Topic: Mofo
Replies: 51
Views: 893

Re: Mofo

At least it will be able to breathe now.
20200520_214925_copy_768x1024.jpg
20200520_214953_copy_1024x768.jpg
The front top plate needs drilling, painting and fitting properly, hopefully on Friday
by steve s
Wed May 20, 2020 10:49 pm
Forum: Everyones Projects
Topic: Resistors
Replies: 47
Views: 1251

Re: Resistors

I'll second that.. Very interesting..
by steve s
Wed May 20, 2020 1:23 pm
Forum: Buying and Selling
Topic: WANTED. Hammond 126C
Replies: 18
Views: 309

Re: WANTED. Hammond 126C

It was a 2a3 i remember i thought it was one of the best amps id heard at that point and it changed my mind about modern 2a3s
Nice to hear it still going.
by steve s
Wed May 20, 2020 12:41 pm
Forum: Everyones Projects
Topic: Mofo
Replies: 51
Views: 893

Re: Mofo

And a pic..
The crackling was due to the 1930s valve bases not been cleaned enough
School boy error..
20200520_123514_copy_768x1024.jpg
by steve s
Wed May 20, 2020 12:32 pm
Forum: Everyones Projects
Topic: Mofo
Replies: 51
Views: 893

Re: Mofo

I've had it on all last night and this morning trying to pic holes in it.. just seems to be getting better.. Unlike many of you, i can't leave it on a board with the grandkids (when they come eventually come) I built a chassis a few weeks ago im going to spend this afternoon wondering how i can get ...
by steve s
Wed May 20, 2020 12:15 pm
Forum: Everyones Projects
Topic: Mofo
Replies: 51
Views: 893

Re: Mofo

Ahhh. Not realised the 'shock' mojo is a funny one..
No problem mark..