Author Topic: Refurbishment of R2R  (Read 7840 times)

Offline vitavoxdude

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Refurbishment of R2R
« on: January 01, 2014, 12:48:49 AM »
 :)  Well I thought I'd just scare you witless by showing you some typical internal pictures of a R2R which I am giving the once over.  :o The kit of parts came from Nagravox advertised on Ebay.  140+ capacitors of dubious quality  :-X but certainly better than the 20+ year old tantalums and 'other' electrolytics.

Most of the boards come out OK but some of them needs a special note of all the screws and cables. ???

I was shocked when I looked at the circuit diagram as there is only a single LM317T regulator for the majority of the daughter boards.  :o The mains transformer looks a decent C core and there are two voltage rails for the entire machine. :'(

How the hell these machines can sound soo good is a mystery to me, if it was a power amp it would be laughed out of the room.  :P Component quality is errhmmm, basic and functional, :-X just what it could do with a more refined circuit.......well an outboard valve stage is probably the only way due to the complexity as others have done.

Have a look at the images below to see what a pigs ear of a design... :-[.........well IMV.  Guess that the seperate boards allow quick substitution in the event of a failure.
V ::)
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline stevenvalve

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Re: Refurbishment of R2R
« Reply #1 on: January 01, 2014, 01:53:26 AM »
Why does it still sound good. Probably because the medium is so good in the first place, even all this sh!t in the way can't completely destroy it.

Offline ozmillsy

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Re: Refurbishment of R2R
« Reply #2 on: January 02, 2014, 09:26:36 AM »
We *have* to take the feed off the heads guys.

It's got to be the goal for 2014.
It's all about the music,, not the equipment.

Offline hedalfa

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Re: Refurbishment of R2R
« Reply #3 on: January 02, 2014, 03:09:34 PM »
Vitavox this is shocking, its not logical that it sounds any good with all that gear in the way.

Yes interesting idea, straight from the heads........

Offline kajak12

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Re: Refurbishment of R2R
« Reply #4 on: January 02, 2014, 04:09:06 PM »
Have you managed to leave the workshop yet vitavox? do you need more solder?
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline vitavoxdude

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Re: Refurbishment of R2R
« Reply #5 on: January 02, 2014, 04:58:53 PM »
Have you managed to leave the workshop yet vitavox? do you need more solder?

Nope, it's an ongoing job, some one beat me to changing some caps and broke tracks on some of the PCB's.  :(  I will get the 'daughter boards' completed first then move onto the serious dismantling stuff later.  Trouble is looking at the replacement caps purchased with the thought 'complete poop quality' running through my brain kinda puts the brakes on! :'(
V
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline vitavoxdude

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Re: Refurbishment of R2R
« Reply #6 on: February 14, 2014, 01:02:02 AM »
Love is..................
V
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline gamve

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Re: Refurbishment of R2R
« Reply #7 on: February 14, 2014, 04:32:08 PM »
Scary. Looks like $2000 worth of work into a machine worth $700 when your finished.  :'(
Get a decent studio machine, do the work on it and keep it. Much better idea  ;D

Offline hedalfa

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Re: Refurbishment of R2R
« Reply #8 on: February 14, 2014, 08:02:40 PM »
Scary. Looks like $2000 worth of work into a machine worth $700 when your finished.  :'(
Get a decent studio machine, do the work on it and keep it. Much better idea  ;D

Logical definitely, but sometimes we want to take on a challenge, yep maybe crazy :o :o :o :o
Its the journey and the destination... Maybe its an excuse to have some Man cave time.....  :P :P :P

Offline vitavoxdude

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Re: Refurbishment of R2R
« Reply #9 on: February 15, 2014, 02:05:13 PM »
Scary. Looks like $2000 worth of work into a machine worth $700 when your finished.  :'(
Get a decent studio machine, do the work on it and keep it. Much better idea  ;D

Yup agree, but I have the time at some points so will finish it, I would not want to pay someone to do it as it many hours work.  :o I notice that a lot of people are jumping on the bandwaggon and charging in excess of 1K for similar R2R's on flebay. :( :( :( 

I am in the market for a big bad Studer  ;D but all those I have bid on have gone for 3 times what I think they are worth......................Anyone with a decent one not requiring recapping/heads/transport bearings/brake belts?  A little bit of TLC I can manage but a complete overhaul........hmmmmm. :-X
V
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline ozmillsy

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Re: Refurbishment of R2R
« Reply #10 on: February 15, 2014, 04:20:02 PM »
Whats the point in owning a Studer, if you're unwilling to pay $125 per original yarlung master tape?

Dubs lose some magic, even a 2% drop, just isnt the same.

I'm listening to a yarlung original as I type (Janacki String trio),  and it is spooky real.   Just amazing.
It's all about the music,, not the equipment.

Offline vitavoxdude

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Re: Refurbishment of R2R
« Reply #11 on: February 15, 2014, 04:33:04 PM »
Whats the point in owning a Studer, if you're unwilling to pay $125 per original yarlung master tape?

Dubs lose some magic, even a 2% drop, just isnt the same.

I'm listening to a yarlung original as I type (Janacki String trio),  and it is spooky real.   Just amazing.

Yes agreed second/third/fourth generation copies will loose something.  Who said I was not willing to buy earlier generation copies? I asked SV which one's he thought worth while having for their musical content rather than original fi.

The electronics in replay are severely compromised and will make more difference that a 2nd or 3rd gen tape IMV.

A wise man does with a cent what others take a dollar to achieve.
V ;D
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline ozmillsy

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Re: Refurbishment of R2R
« Reply #12 on: February 15, 2014, 04:41:37 PM »
Buying a Studer is not talking cents,   even buying a sh1t one is expensive.

So we're not talking cheapy kit.

Yarlung has only released 8 tapes, in 2 seperate series.  If you buy each series in a set, they're cheaper ($50 discount per set).   All of them are worth owning, given their sonic quality.   There is only 1 out of 8 that wasnt to my taste,  but I have still played it many times, and have grown to appreciate it.

If you're aspiring for the best hardware, you may aswell get the best software, especially when that software is miles in front of the competition in terms of both price and performance.
« Last Edit: February 15, 2014, 04:59:13 PM by ozmillsy »
It's all about the music,, not the equipment.

Offline vitavoxdude

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Re: Refurbishment of R2R
« Reply #13 on: February 15, 2014, 05:05:35 PM »
Hi Oz  ;D

Having to earn my living makes me a lot more careful what I spend it on and buying tapes which I do not enjoy the music makes no sense to me whatsoever hence my enquiry to SV.  :) Whilst I too would probably appreciate the quality of the recording it has to move me emotionally to want to own it.  :-* One reason I bought the KDAC was it stood out musically. 8)  Anyway I am not disagreeing with you.   There are lots of examples where spending the most does not always bring long term satisfaction. :-X

Studer's are not cheap, that's a given but one day I will own one or similar, nothing surer than that, I already have 2 R2R recorders and in each case its the audio replay circuits that lets them down.  Maybe I should just buy the TP head amp for the Revox.  About time some of the Valve heads amongst the readership came up with a great circuit to replay as mentioned before, hint hint.  :P :P :P
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline ozmillsy

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Re: Refurbishment of R2R
« Reply #14 on: February 15, 2014, 06:10:21 PM »
Maybe I should just buy the TP head amp for the Revox.  About time some of the Valve heads amongst the readership came up with a great circuit to replay as mentioned before, hint hint.  :P :P :P

I personally find music infinitely more engaging, when the sonics are to die for. Music takes new meaning.  I'm not generally a classical fan, let alone chamber music.  But I love these Yarlung tapes.

None of us on this site are millionares.  We all work for a living.  In my case, I am the sole income earner for our household,  and hence not in a position to squander money (despite what some may think).

I'd love to find how big a step up it would be to tap direct off the heads, and bypass all the crud that appears to be shoved into our r2r machines,  bypass with a simplified tube based output stage.    I refuse to import such an output stage, as  I have no idea what I am getting (not prepared to gamble on it).

For now, I enjoy what I have.
It's all about the music,, not the equipment.