New Arrival

Ray P · Post by **Ray P** » Thu Jul 15, 2010 8:14 am

Hi Chaps,

I've been "off-line" with some distractions lately. Anyway, yesterday I finally finished my Transcendent SE-OTL amplifier and plugged it in.

I made some changes to the stock kit, most obviously replacing the exposed toroids od the original with potted versions, relocating the power supply chokes inside the chassis, adding a passive volume control and replacing the front panel.

I also relocated the on/off switch to the rear panel to avoid running AC cables across the amplifier (hence the new front panel). I retained the stainless steel chassis, which polishes up nicely. I think my version looks nicer than the stock version - see attached picures.

Component wise, I threw in some HexFred diodes, jupiter caps, kiwame and takman resistors and silver wire for signal paths, plus a few other 'tweaks'.

I've had the amplifier playing for just a couple of hours so it isn't burned in, plus I've got brand new Lowther EX4 units in my horns (upgrade from EX3s but also changed from 8ohm versions to 15ohm versions) so definitive conclusions are some way off, however, first impressions are very positive. The sound has more 'bite' than my Bottlehead Paraglows and there is a tremendous amount of detail; my partner commented about how good it sounded, which is always a good sign as she is a musician and has no interest in hifi.

I'll post further on my impressions as everything beds in.

Ray

chris661 · Post by **chris661** » Thu Jul 15, 2010 8:22 am

Beautiful, that.

Ali Tait · Post by **Ali Tait** » Thu Jul 15, 2010 1:44 pm

Lovely job!

Mike H · Post by **Mike H** » Thu Jul 15, 2010 2:36 pm

Yes indeed! Lot of work too.

Ray P · Post by **Ray P** » Sun Jul 18, 2010 9:25 pm

I've attached some additional pictures for anyone interested in the internals.....

Ray

andrew Ivimey · Post by **andrew Ivimey** » Sun Jul 18, 2010 9:44 pm

well knock me down with a feather; I have an OTL futterman design with two 6AS7s per side and I've never thought about trying it with Lowthers but given the speed of the Sidcup Screechers and the speed of OTL, this could be a marriage made in audio nirvana.

I'll try it.

Ray, you got me started on this single driver stuff with those fostex167s and a pile of baltic ply - thanks a lot!

oh I know I'd have had to get on with Lowthers eventually but 167s were a very gentle way in.

Ray P · Post by **Ray P** » Mon Jul 19, 2010 2:07 am

Andrew, if you're ever in this neck of the woods again you would be very welcome to a cup of tea and a listen.

I'm not sure if the SE-OTL is actually better than the Bottlehead Paraglows but it is different and it is so quiet wrt hum etc. through the lowthers. I'm finding that I prefer it at the moment; will be interesting to see if that lasts.

Ray

chris661 · Post by **chris661** » Mon Jul 19, 2010 8:38 am

The internal wiring is certainly... interesting...

Glad it works, fault-finding would be fun to say the least.

Ray P · Post by **Ray P** » Mon Jul 19, 2010 9:08 am

chris661 wrote:The internal wiring is certainly... interesting...

Glad it works, fault-finding would be fun to say the least.

It's as close to the layout specified by the designer (Bruce Rozenblit) as I could get it - in order to minimise noise he invested a lot of time positioning components and routing the cabling and he succeeded because it is very quiet. A lot of it is star earth wiring.

Building it this way was against my normal tidy approach but I think Bruce knows more about these things than I do.

Ray

andrew Ivimey · Post by **andrew Ivimey** » Mon Jul 19, 2010 9:47 am

yeah me too - my excuse anyway!

Post by **Nick** » Mon Jul 19, 2010 9:59 am

chris661 wrote:The internal wiring is certainly... interesting...

Glad it works, fault-finding would be fun to say the least.

You might find that its a lot simpler than if the wires are all tied together into neat looms. Remember the electrons dont know or care about our Victorian notions of order

On a more practical front, two wires at right angles interfere far less than running parallel, and the inside of a amp is a 3D space, no need to confine things to a plane.

pre65 · Post by **pre65** » Mon Jul 19, 2010 10:05 am

One of the V-8 cars I had in my yoof had to have one plug lead laid out in a special way cos otherwise an adjacent lead would induce a spark at the wrong time that could have caused engine damage.

Must have been the Sunbeam Tiger with the Ford (USA) small block 260 cu in engine. (4261 cc)

Post by **Nick** » Mon Jul 19, 2010 10:44 am

pre65 wrote:One of the V-8 cars I had in my yoof had to have one plug lead laid out in a special way cos otherwise an adjacent lead would induce a spark at the wrong time that could have caused engine damage.

Must have been the Sunbeam Tiger with the Ford (USA) small block 260 cu in engine. (4261 cc)

I bet you were loved by local radio listeners

pre65 · Post by **pre65** » Mon Jul 19, 2010 11:17 am

Nick wrote:
pre65 wrote:One of the V-8 cars I had in my yoof had to have one plug lead laid out in a special way cos otherwise an adjacent lead would induce a spark at the wrong time that could have caused engine damage.

Must have been the Sunbeam Tiger with the Ford (USA) small block 260 cu in engine. (4261 cc)
I bet you were loved by local radio listeners

It was like Blackpool illuminations at night with the bonnet up.

It was that, together with a weak 2BB carb shut off float valve and an SU electric fuel pump that caused the underbonnet fires.

Ray P · Post by **Ray P** » Mon Jul 19, 2010 11:41 am

BTW, it's not just Mr Ivimey who is welcome to a cup of tea; anyone passing this way is welcome...

Ray

audio-talk

New Arrival

#1 New Arrival

#2

#3

#4

#5

#6

#7

#8

#9

#10

#11

#12

#13

#14

#15