[london luke]

So here it is...... Click on pic for more detailed photo. There are photo's of the circuit etc here: inside pics


Next job is to sort out feet..maybe use matching spiked ones as on CDP????

What has realy changed in such a short time is the "X feed" I am glad that it is fitted.. Its a very interesting device. Must learn to master it.

To those who have never seen them..the funny looking headphones are original "Jecklin Floats" very open sound. Limited bass...... but vocals are out of this world... Would love to have HD600's bass to match.

For anyone wanting to know further technical details.... You need to ask Richard:

 

[davidmiya]

Whoa! I love the brushed aluminum faceplate and the shiny pot. I sure hope it sounds as good as it looks

 

[lextek]

Very, nice looking. Great job.

 

[RichardH]

I'm the bod who built it, but I can't claim credit for any of the tweaks to the standard device - they were gleaned from various places - from PinkFloyd here, and from Andy Weekes over at the Pink Fish Forum (and elsewhere!).

Basically, it's a Hart Andante power supply and Chiarra headamp in a single box.

The box
Luke sourced the box (and chromed switch and knob) from Italy - not too pricey, but the fit and finish aren't as good perhaps close up as it looks from the pic. It has aluminium extrusions as side plates, and the alu front and back panels screw on to this with countersunk allen bolts (supplied with the case). You get one panel in brushed black and one in the alu finish as seen in Luke's pic - your choice as to which becomes the front. Top and bottom of the amp are steel, and have vent slots.

Power supply changes
Replaced the caps around the regulator with Elna Stargets - 47u's replacing c1/c9 and 22u's replacing c2/c10.
Replaced the LM7815 and LM7915 with LM7812 and LM7912, so it is now supplying +-12v rather than 15. Uprated heatsinks on the regs, as they now need to drop an additional 3v, and the supplied 'sinks were getting rather hot.

Chiarra changes
Nothing much changed here - balance pot removed, and an alternative opamp has been put in. I've used the AD8620, which needs a Brown Dog adapter to go into the DIP8 socket. It also requires a max of +-12v, hence the change of regulators in the PSU.

Crossfeed
Final alteration was to add one of PinkFloyd's crossfeed devices. In discussion with Luke, he liked the idea of being able to switch the crossfeed in and out, hence the slightly OTT solution: the signal goes to a PCB containing two 12v changeover relays. A separate 12v regulator on the Andante gives a 12v supply, which is switched between the relays with the front panel toggle switch. The relays are set so that applying power to the relay switches the input OFF, so the active one has no power from the relay near it. I think Luke may well decide to lose the switching once he decides which version he prefers.

Interestingly, when first powered up, it was hard to spot the effect of the crossfeed, but as the amp got going, the effect became more pronounced. I'll be interested to hear Luke's comments once it's all burnt in.

Richard

 

[london luke]

Ok... the firs 100 hours odf solid burning has been done.

I will only use 3 cds to judge it.
1. "Hell freezes over"
2.Alison Moyet " Hoodoo"
3."Ac/DC" The razors edge.


Its about a good a cross reference of the type of music that I like!!


Ok here we go...... Its very difficult to learn to relax listening to headphones after many years of listening to excellent speaker hifi!!

maybe I need some advice.... I am trying to get the sound to have some forward stage.......

The "Xfeed" this takes a lot of getting use to...... It takes the edge of the treble a fraction..


Theres a lot I like but another lot of stuff I must get use to!!

I am happy with the set up. I am using a "Oehlbach pure silver ref series interconnect" I do also have a "Ixos"1002 Gamma" interconnect.... Something about the silver one I like..but The Gamma has a fraction better bass. maybe after a fewmore hundred hours things will change.

The Midrange is very smooth and I like it...But not its positioning

Just hor forward a soundstage can be achieved??and how much would it cost!!!

Other basic things....... The amp is quiet... And I like it. Its difficult to compare it against "Nothing"!!!!! But if I had payed £300.00 for it in a shop I would be happy. I only tried the main other amps in shops and this is much better.


Also its speed is getting better on the bass... If it just gets better then great.It firm and fast. Also well seperated .



Always willing to learn


Luke

Ps: Richard

that LED is bloody bright!!!! what resistor should I use??

 

[RichardH]

You have mail, Luke.

R

 

[Mat Bon 0013]

Hey! Nice job Richard, Luke interesting to hear some impressions of the Chiarra

 

[PinkFloyd]

Hi Luke,

That's looking great! Richard has done a nice job by the looks of things

I'm not surprised the crossfeed is losing treble going through all those relays and switches, you would have been better served using a standalone X-Feed to keep the signal path as simple as possible. I doubt if you'll be hearing the chiarra at its best either employing those relays but, as Richard says, it will give you a "rough" idea of the sound and you can decide on one or another at a later date and take the input signal either direct to the PCB or through the X-Feed.

I would personally take the input signal direct to the chiarra PCB and use an external crossfeed...... it's inconvenient having to disconnect the interconnects but I really do think you'll get the best sound quality this way

One thing I can say about this amp......... it needs one hell of a burn in period before it starts singing, mine really came into its own after about 6 months!

See how it goes but I'm sure Richard will agree that the relays and switch will have to go.

Looking good

All the best.

Mike.

PS: Meant to ask why you only fitted the one headphone socket?

http://freespace.virgin.net/borders....insleyhood.htm

 

[RichardH]

Quite agree, Mike. I'm sure Luke will be sending it back up for a re-fettle at some point.... or doing it himself

We did discuss having separate inputs for the with and without crossfeed, but Luke fancied the relay solution, certainly in the short term.

 

[JMedeiros]

It looks fantastic. You DYI guys are gods.

 

[RichardH]

One headphone socket - Luke fancied as clean a front panel as poss, and he never envisaged listening with two pairs of phones at the same time, so.... one socket. Only the socket is missing, not all the circuit components behind the scenes.

I was happy as it was one less hole to get in the right place on the front panel

As I understand it, both sockets are identical, though it would be possible (if you knew what you were doing - i.e. not me) to alter them so you catered for different impedence 'phones.

 

[PinkFloyd]

Quote:

Originally posted by RichardH One headphone socket - Luke fancied as clean a front panel as poss, and he never envisaged listening with two pairs of phones at the same time, so.... one socket. Only the socket is missing, not all the circuit components behind the scenes. I was happy as it was one less hole to get in the right place on the front panel As I understand it, both sockets are identical, though it would be possible (if you knew what you were doing - i.e. not me) to alter them so you catered for different impedence 'phones.

Right enough Richard, no need for 2 sockets unless you're into "dual" listening

Do you have any of those brown dogs going spare? I wouldn't mind slotting one in just to hear the difference over the 8 pin varieties

is it just a case of plugging it into the 8 pin socket?

Mike.

 

[RichardH]

Yes, it just drops into the DIP8.
I don't have one with an AD8620 spare, but you'd be welcome to borrow mine if you want.
Alternatively I do have a blank Brown Dog spare if you have an AD8620 around the place - I bought one extra in case I cocked up

EDIT - remember you need a +-12v supply rather than the 15 as per standard Chiarra.

Drop me a PM or mail.

Richard

 

[london luke]

Hello Richard and Mike

This is a complete learning curve for me. This amp can be modded in anyway we want.... its a open test bench kind of thing!!!!


Mike ..I will let things run for another week.... (Which version of the Xfeed do I have??) Then I think it should be hard wired into the amp???? Remove the switching as suggested... It was a great way of switching though!!.

maybe if it will need a lot of work we should put the new version 4... (Can you stop and let us all save for a bit!!) or could mine be modded???

I would like to keep the x feed inside to keep it all together.

What to do with the redundant switch???..... Maybe put the power switch on to the front?????


Come on lets have some fun!!


Cheers for all your time

luke

 

[PinkFloyd]

Quote:

Originally posted by london luke Hello Richard and Mike This is a complete learning curve for me. This amp can be modded in anyway we want.... its a open test bench kind of thing!!!! Mike ..I will let things run for another week.... (Which version of the Xfeed do I have??) Then I think it should be hard wired into the amp???? Remove the switching as suggested... It was a great way of switching though!!. maybe if it will need a lot of work we should put the new version 4... (Can you stop and let us all save for a bit!!) or could mine be modded??? I would like to keep the x feed inside to keep it all together. What to do with the redundant switch???..... Maybe put the power switch on to the front????? Come on lets have some fun!! Cheers for all your time luke

Put the power switch on the front, remove the x-feed circuit and listen to the amp in its unmodified state for a while and then try a standalone crossfeed to evaluate the differences.

If you are convinced it sounds better with the standalone crossfeed then adopt that approach and hard wire an X-Feed circuit inside the amp.

I'd be inclined to go for the "listen to the amp as it is" approach first and foremost. Thing is, I can't comment as your amp is running off a 12V supply as opposed to the 15V standard.

Totally new territory for me Luke, I can only really comment on the original kit with the 15V supply and the modifications I made to that unit....... the 12V browndog scenario is way beyond anything I would contemplate and something I wouldn't consider implementing.

The kit runs around a 15V supply and I believe it performs best utilising the original design, any variations on the design are at the owners risk but I reckon it would be a good idea for you to hear the original amp before modifying it.

Mike