High-ohm grid resistor in tube (pre)amp design
in [Design]
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From: christofire on 12 Nov 2009 21:43 "Phil Allison" <phil_a(a)tpg.com.au> wrote in message news:7m3ud1F1hbblqU1(a)mid.individual.net... > > "christofire" > >> WEM carried on making the 'Copycat' with a tape loop and an AC induction >> motor long after bucket-brigade devices had become available, > > ** The original valve WEM Copicat was never more than a cheap and > cheerful device for impoverished guitarists - subsequent WEM models were > only marginally better. > > Much better preforming but more expensive units existed, like the Klempt > and the famous Binson Ecorec - the latter using a rim driven drum which > eliminated most of the horrible problems experienced with tape loops. > > There are still no readily available digital units that produce the same > kinds of sound effects possible with these mechanical units. > > > .... Phil I've seen your photo of the (futuristic?) 120 mm drum elsewhere but I've never had the opportunity to examine one in detail. Was the rim of the drum coated with oxide in some way like tape, or was it just a steel drum? Chris
From: Phil Allison on 12 Nov 2009 21:59 "christofire" > "Phil Allison" "christofire" >> >>> WEM carried on making the 'Copycat' with a tape loop and an AC induction >>> motor long after bucket-brigade devices had become available, >> >> ** The original valve WEM Copicat was never more than a cheap and >> cheerful device for impoverished guitarists - subsequent WEM models were >> only marginally better. >> >> Much better preforming but more expensive units existed, like the Klempt >> and the famous Binson Ecorec - the latter using a rim driven drum which >> eliminated most of the horrible problems experienced with tape loops. >> >> There are still no readily available digital units that produce the same >> kinds of sound effects possible with these mechanical units. >> > > I've seen your photo of the (futuristic?) 120 mm drum elsewhere but I've > never had the opportunity to examine one in detail. Was the rim of the > drum coated with oxide in some way like tape, or was it just a steel drum? > ** The Binson drum was made up from several parts. 1. A machined aluminium ring of about 10mm square cross section and 120 mm in diameter. 2. A thin, *continuous* steel band about 7mm wide, shrink fitted onto the above ring. 3. A pressed steel disk that held a 12 mm steel centre shaft and the above ring. The surface speed of the steel band was about 410 mm per second or 16 ips. ..... Phil
From: christofire on 13 Nov 2009 00:35 "Phil Allison" <phil_a(a)tpg.com.au> wrote in message news:7m40c0F3deko9U1(a)mid.individual.net... > > "christofire" >> "Phil Allison" "christofire" >>> >>>> WEM carried on making the 'Copycat' with a tape loop and an AC >>>> induction motor long after bucket-brigade devices had become available, >>> >>> ** The original valve WEM Copicat was never more than a cheap and >>> cheerful device for impoverished guitarists - subsequent WEM models were >>> only marginally better. >>> >>> Much better preforming but more expensive units existed, like the Klempt >>> and the famous Binson Ecorec - the latter using a rim driven drum >>> which eliminated most of the horrible problems experienced with tape >>> loops. >>> >>> There are still no readily available digital units that produce the same >>> kinds of sound effects possible with these mechanical units. >>> >> >> I've seen your photo of the (futuristic?) 120 mm drum elsewhere but I've >> never had the opportunity to examine one in detail. Was the rim of the >> drum coated with oxide in some way like tape, or was it just a steel >> drum? >> > > > ** The Binson drum was made up from several parts. > > 1. A machined aluminium ring of about 10mm square cross section and 120 > mm in diameter. > > 2. A thin, *continuous* steel band about 7mm wide, shrink fitted onto the > above ring. > > 3. A pressed steel disk that held a 12 mm steel centre shaft and the > above ring. > > The surface speed of the steel band was about 410 mm per second or 16 ips. > > > > .... Phil Amazingly complicated, but it did the job so effectively. It's a shame the Boss RE-20 has feedback from all the delays instead of just the longest one, otherwise it could have made a good job of the Meazzi. Chris
From: ChrisQ on 13 Nov 2009 04:56 christofire wrote: > > What's a 'Watkins AC30'? The well-known AC30 certainly wasn't one of > Charlie Watkins's creations. > > Chris(a different one)tofire > > Quite right, memory fades. The AC30 was by Vox, from the 60's initially and later reintroduced by the company in the late 70's. 4 x EL84 in the output stage, iirc... Regards, Chris
From: ChrisQ on 13 Nov 2009 05:02
Phil Allison wrote: > > > ** Done regularly as part of amp testing. Sure, man, sure and the cheque's in the post, right ?... Regards, Chris |