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Green Wagon

FS: BNE: DIY -> DCB1 <- volume control. (sorry my bad, NOT an LDR pre)

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Guys, I am so sorry. I stuffed up really badly here.

 

 

This is NOT an LDR pre, It is a DCB1 Which is a Pass B1 Buffer With a Salas shunt reg.

 

 

So I was half right..... more info on the DCB1 Here --> http://www.diyaudio.com/forums/analog-line-level/171715-salas-hotrodded-blue-dcb1-build.html

 

 

Item:  DIY LDR DCB1 'passive' pre with remote volume. (NO remote control supplied - use a universal one) And NO power cord supplied.

Location: Kenmore Qld

Price:  $500 Plus cost of shipping.

Item Condition: Puurfect.

Reason for selling: Surplus to requirements.

Payment Method: Bank transfer / Cash

Extra Info:

 

Dimensions: Overall dimensions are 87h 280d 405w (mm)

 

This is a bit of gear I built 4 years ago, usual throw money at it till its what I wanted deal.

 

Case is aluminum sheet that was laser cut, machine folded, then had the corner seems tig welded.

It's been powder coated white, then the outside powder coated black. Lid is the same and is secured with 4 stainless hex screws into rivnut's.

Front panel is brushed 5mm aluminium (Was a bit of left over hence the machined groove on the back of it) that is secured to the chassis with 4 stainless hex screws and stainless nylock nuts.

Knobs are machined from solid aluminium then bead blasted. (ebay - cost me a bit)

 

Potted and encased 50va toroidal transfomer feeds both boards.

 

DCB1 board is Salas shunt regulator DCB1 board from DIY Audio.

The Fets and shut regs are all hand matched.

The regs can be bolted the case (to act as a heatsink) and resistors changed to increase the current through them. This is supposed to improve the sound further.

 

The remote board is from altronics and is designed to be used with any universal remote control.

 

All caps throughout are Panasonic FC's

 

Final words;

Four inputs (NOT remote controlled) and two (parallel) outputs. (Dad wanted to drive amp and wireless headphones without swapping plugs)

It is dead silent in use.

Sonicly it is really close to the pass labs x2.5 pre that he got to replace it.

The 2.5 is just that smidgen cleaner and more extended in the treble, But it really is close.

 

Just remember, this is a 'passive' pre, so 1v in = 1v out.

 

Pictures:

 

Left to right, four input rotary that switches input relays (can be altered to six inputs) - Alps motor driven level control (This only controls drive current to the LDR's) - rotary power switch (That cost me over $50 alone).
 

post-106429-0-27948800-1458895679_thumb.

 

Back board is the LDR DCB1 , front board the remote reciever.

 

post-106429-0-02131000-1458895690_thumb.

 

Back, Filtered IEC socket and fuse, two outputs, four inputs.

 

post-106429-0-28413700-1458895701_thumb.

 

Dirty lid, it will be cleaned before shipping/pick up.

 

post-106429-0-06922000-1458895710_thumb.

 

 

 

 

ELECTRICAL DISCLAIMER
This product has not been manufactured by a qualified individual or company, therefore contains electrical circuits that do not necessarily comply with Australian Standards. I understand that as the seller, I may be liable to repercussions in the event of equipment failure. By advertising and selling this product, as the seller I also agree that I am solely liable, and the publisher of this website takes no responsibility for any injury or death resulting from, whether directly or indirectly, any accident that may happen as a result of the failure of the product being sold. If in doubt, seek the services of a qualified electrician to inspect the product to ensure it is safe for use.

Edited by Green Wagon

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Mmmm you have lavished time $$$ and most importantly expertise on this.

Tempted even though I have no (immediate) use for it

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But thats always the problem with 'hobbies' of any sort.

We can never have enough of the bits and trinkets  :D ............

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If only it had remote control function

Unless you can add one ?

As I'm getting older I want to stay in my seat and adjust the volume GLWS

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If only it had remote control function

Unless you can add one ?

As I'm getting older I want to stay in my seat and adjust the volume GLWS

It already has one Paul and these sound good.

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Guest Muon

Yup, motorised pot, supply own remote control as per OP.

 

Mmm..tasty item.

 

GLWTS GW.

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Thanks lads - I read no remote for selector switch but it has a volume switch

I really only need a remote volume unit for my pre

But this intrigues me

I better have a chat with Nigel to see if it would suit the FW F6

And if he can fit in a Nelson Pass phono amp unit

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Clarification...

 

It has a remote volume control, but i dont have an actual remote for it. So if you buy (or have) a programmable remote, you will be able to control the volume. Heck, the remote you have may even work with this as is...

 

Input selector and power are not remote controllable at all (as it sits)

If you wanted remote input switching, youd have to replace the remote receiver board and do a little rewiring. (input selection is low power relays so thats pretty easy)

 

Fitting into other gear, maybe possible depending on space, but the LDR's arent a fan of heat from memory.

 

edit, from memory its a standard phillips ir coding. and if you have a 'mute' button, it will wind the volume all the way down.

 

edit two - remote kit is this one -

 

http://www.altronics.com.au/p/k5026-remote-volume-control-kit/

 

(Silicon Chip Magazine June ‘02)Add a remote control volume to your latest audio project or amplifier. Ideal for building into amplifiers or pre-amps.

It features PIC controlled precision and a motorised pot so the knob will move when you adjust the volume!

It can even mute the volume at the press of a button. Altronics recommends the A 1012 remote control to suit this kit.

Edited by Green Wagon

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ah poo cakes.

Im so sorry, I fd up big time.

 

this is NOT an ldr pre.

It is actually a DCB1.

 

How did i screw that up..

 

Im so soo sorry guys........

Edited by Green Wagon

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Superb build Nigel.

I just love the powder coated internal look - well done!

How much DC offset on the output?

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Thank you sir *bows* :)

 

Short version, had the case made were I worked, due to multiple areas and stages, I lost track of it for a day, and it went through the normal white powder before I found it again.

So I asked if they could do the outside and lid in black, so it got masked up and done a second time...

so its a full white powder, then a second coat with black for lid and external...

 

DC, I have never measured it.

It is dc coupled and never given any noise that we've heard. (Actually, now I have a scope again, I might just see what it's like :D )

The original B1 is supposed to go to 700khz at -3db

The Toshiba 2SK170 are rated to 5mhz, so if you changed the volume pot to a 10k, you should double its response out to 1400khz

 

It is a pass B1 buffer, which is a simple transistor stage to (as it says) buffer input from output.

Salas then made a run of boards with his 'shunt regulator', input switching, and a few other little tweaks.

That created the 'Salas DCB1'.

 

If I get the chance i'll measure it today and report back :D

 

Heres the original B1 from Nelson Pass - http://www.firstwatt.com/b1.html

 

 

 

EDIT -> DC out as best as I can measure is around 0.2 milli volt. ( 200 micro volt)

Thats with input and output unloaded, So I'd expect it to drop even lower when connected an amp.

Edited by Green Wagon

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Thanks for all the detailed information Nigel.

.2 milli volt DC offset unloaded is excellent! No problem connecting that straight up DC coupled power amp.

I hand trim my DACs to under a milli volt & thought that was pretty good.

So the white internal was a mistake - for a mistake I think it looks pretty darn good.

You should email Papa Nelson a photo - might start a new trend.

I'd love to do that with my DACs but I have feeling it would cost way too much.

Guys this is a real bargain, someone should grab this real quick.

GLWTS

Cheers Clay

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More than welcome Clay :)

 

Nelson really comes out with some amazing products.

And then the guys at diyaudio take it several steps further.

Just look at all the spin offs of the B1. - B2, B3, balanced, bi amp, tri amp.....

1mv for any device is impressive. Most amps are 100mv, and ive seen some at 500mv  :unsure:

 

White wasn't so much a mistake. I did want white inside black outside. Thought they could do it as a two color and one bake. Ended up as two bakes.

Easy to see whats going on with a light color interior.

Amp I built decades ago (AEM6000) I sprayed the inside off white ('Mushroom' from memory). Makes a huge difference.

 

For your dacs, maybe mask up and just spray the insides white or whatever ?

Pick the right paint and it'll be hard wearing. But it will show up flux splatters etc...

If the bottom panel is detachable, just powder the one side of that. Quick cheap easy...

Powder coating has come alooong way. amazing what can be done now.

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I have had a home trial with this unit

Connected to my First Watt F6 clone 25W amp

Firstly

This pre is as quiet as a "dead church mouse" and that's on speakers of a min of 104db

Very pure and revelling sound - it's just effortless

I really don't need to make a colourful review as it's just so good

Happy to field any specific questions

Only thing stopping me from taking it off @@Green Wagon 's hands is my wife has spotted it

And you all know that look

And for her it means that it's eating away at the cruise holiday savings

I thought I would sneak it in under the radar but she sniffed it out

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I second Paul's comments. Nigel built two of these, one for his Dad and one for himself. I bought Ngel's own unit from him. These are superbly built and a sonic bargain but I can't justify owning two.

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I have had a home trial with this unit

Connected to my First Watt F6 clone 25W amp

Firstly

This pre is as quiet as a "dead church mouse" and that's on speakers of a min of 104db

Very pure and revelling sound - it's just effortless

I really don't need to make a colourful review as it's just so good

Happy to field any specific questions

Only thing stopping me from taking it off @@Green Wagon 's hands is my wife has spotted it

And you all know that look

And for her it means that it's eating away at the cruise holiday savings

I thought I would sneak it in under the radar but she sniffed it out

 

Ta Paul, out of curiosity, hows it go for end volume in your system ?

 

 

I second Paul's comments. Nigel built two of these, one for his Dad and one for himself. I bought Ngel's own unit from him. These are superbly built and a sonic bargain but I can't justify owning two.

 

Yes you can :P

Second one for the shed where youll be sleeping when 'she' finds out youve bough another............

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On my system I get volume @ 9.00 o'clock and it's good listening level @ 12 o'clock to 1 o'clock

It's a lovely little unit

On/Volume knob starts at approx 6.35 o'clock

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Yes you can :P

Second one for the shed where youll be sleeping when 'she' finds out youve bough another............

Not sure that she knows that I bought the first one ;)

Edited by Telecine

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