[Duncan]

If you're going for an all out, no holds barred op-amp setup... its gotta be two OPA637s... they're about £18 each from RS... and whatever adapter you'd need to get two mono chips to work in stereo

 

[ServinginEcuador]

In case anyone is interested in this amp, Ray Samuels makes an incredibly good power supply that is fully adjustable up to 18 volts. It can be bought from him at his web site here:

http://www.raysamuelsaudio.com/price.html

His dynamite and extremely well built PS can be bought for $325. A little expensive, but just take a look.

[EDIT] Here's the site with info on his PS:

http://www.raysamuelsaudio.com/new.html#hr2

 

[PinkFloyd]

Quote:

Originally posted by Duncan If you're going for an all out, no holds barred op-amp setup... its gotta be two OPA637s... they're about £18 each from RS... and whatever adapter you'd need to get two mono chips to work in stereo

As it happens Duncan, I've got 3 OPA637's 3 OPA627's 4 AD823's and 4 AD 825's.

Now where can I obtain an adapter?

Mike.

 

[Tomo]

Wait,

Are you sure they are in the signal path? If it is dc-offset correction opamp, then it might not worth paying a lot of opamps.

I would check it since if it is dc offset correction opamp, replacing with OPA627/37 wouldn't make much audible difference. (It will do really good correction, but then you can do without in terms of sound quality.)

If it is in signal path, you should use OPA627/637 and other uber spec opamps. Also, it is not a requirement to use fet input opamps for you can try out AD797 for ultimate low noise.

I got quite few selections of these. I am a bit excited.

Tomo

 

[Tomo]

PinkFloyd -

Adaptors can be obtained thru Tangent's site (http://tangentsoft.net/audio/). Or from BrownDog (http://www.brndog.com/)

Tomo

 

[eddy]

Lucky for me I stumbled across this thread as I am planning on ordering a Chiarra kit on monday (assuming I get paid on time). Its either that or an IPL Transmission Line speaker kit. Think I will go with the Chiarra now (theres allways next month for the speakers).

Just a couple of quick questions...

1) I am currently driving a set of grado SR-80's from the headphone stage on my Rotel RA-930BX integrated amp. Would it be safe to assume that the Chiarra would provide a sensible upgrade? Not that it would put me off if it only sounded a little better as I have been wanting to try my hand at building a dedicated headphone amp for some time.

2) I haven't built any electronics projects since university but I have moderate soldering skills, a fair understanding of basic electronic theory (if rather rusty) and can tell a capacitor from a resistor. Would this project be within the scope of my somewhat limited skills (assuming I take the time to read the documentation properly)?

Anyway, sweet looking amp. Thanks for the pics and review.

Thanks for your time.

Regards

ed

 

[Nisbeth]

Quote:

Originally posted by eddy Lucky for me I stumbled across this thread as I am planning on ordering a Chiarra kit on monday (assuming I get paid on time). Its either that or an IPL Transmission Line speaker kit. Think I will go with the Chiarra now (theres allways next month for the speakers). Just a couple of quick questions... 1) I am currently driving a set of grado SR-80's from the headphone stage on my Rotel RA-930BX integrated amp. Would it be safe to assume that the Chiarra would provide a sensible upgrade? Not that it would put me off if it only sounded a little better as I have been wanting to try my hand at building a dedicated headphone amp for some time. 2) I haven't built any electronics projects since university but I have moderate soldering skills, a fair understanding of basic electronic theory (if rather rusty) and can tell a capacitor from a resistor. Would this project be within the scope of my somewhat limited skills (assuming I take the time to read the documentation properly)? Anyway, sweet looking amp. Thanks for the pics and review. Thanks for your time. Regards ed

I'll leave it to PinkFloyd to respond conclusively to you questions since he actually built the kit, but judging from the pics on the Williams-Hart website it doesn't look like it's too difficult to assemble. If you take your time (think twice, solder once instead of vice versa

) and read the documentation carefully I don't think you'd be in any kind of trouble. One thing though, if you're not entirely confident in your soldering skills, you should perhaps buy a small kit from an electronics store to practice on first.

Best of luck!

/U.

 

[PinkFloyd]

Quote:

Originally posted by eddy Lucky for me I stumbled across this thread as I am planning on ordering a Chiarra kit on monday (assuming I get paid on time). Its either that or an IPL Transmission Line speaker kit. Think I will go with the Chiarra now (theres allways next month for the speakers). Just a couple of quick questions... 1) I am currently driving a set of grado SR-80's from the headphone stage on my Rotel RA-930BX integrated amp. Would it be safe to assume that the Chiarra would provide a sensible upgrade? Not that it would put me off if it only sounded a little better as I have been wanting to try my hand at building a dedicated headphone amp for some time. 2) I haven't built any electronics projects since university but I have moderate soldering skills, a fair understanding of basic electronic theory (if rather rusty) and can tell a capacitor from a resistor. Would this project be within the scope of my somewhat limited skills (assuming I take the time to read the documentation properly)? Anyway, sweet looking amp. Thanks for the pics and review. Thanks for your time. Regards ed

Hi Ed,

The kit is very easy to build but the instructions, in places, could be better. Luckily Shaun Williams will help with any bits of the instructions that don't, at first, make sense or alternately you could e-mail me if your stuck on any part of it. Basically it is just a case of soldering the components into the correct positions on the board and I'm sure you'll manage it if you are good at soldering.

The Chiarra will knock the socks of the Rotels headphone out stage and by quite some considerable margin. Be prepared for a long burn in with the amp though... it really doesn't kick into gear until it has 200 hours + under the bonnet, after the initial burn in period it really starts to sing.

Buy this kit and you certainly will not be disappointed.

All the best.

Mike.

 

[eddy]

Quote:

Hi Ed, The kit is very easy to build but the instructions, in places, could be better. Luckily Shaun Williams will help with any bits of the instructions that don't, at first, make sense or alternately you could e-mail me if your stuck on any part of it. Basically it is just a case of soldering the components into the correct positions on the board and I'm sure you'll manage it if you are good at soldering. The Chiarra will knock the socks of the Rotels headphone out stage and by quite some considerable margin. Be prepared for a long burn in with the amp though... it really doesn't kick into gear until it has 200 hours + under the bonnet, after the initial burn in period it really starts to sing. Buy this kit and you certainly will not be disappointed. All the best. Mike.

Hi Mike,

Thanks for the comments, just what I wanted to know. I am especially pleased to hear that the Chiarra will provide a worthy upgrade over my Rotel.

I will be ordering the kits on Monday if I get a spare minute. On a related note I wonder if you could find the time to answer a couple more quick questions....

1) Did you order online? If so did the process go smoothly?

2) How long did it take for the kits to arrive (roughly)?

Thanks again for your help (and to Nisbeth, much appreciated).

Regards

ed

 

[PinkFloyd]

Quote:

Originally posted by eddy Hi Mike, Thanks for the comments, just what I wanted to know. I am especially pleased to hear that the Chiarra will provide a worthy upgrade over my Rotel. I will be ordering the kits on Monday if I get a spare minute. On a related note I wonder if you could find the time to answer a couple more quick questions.... 1) Did you order online? If so did the process go smoothly? 2) How long did it take for the kits to arrive (roughly)? Thanks again for your help (and to Nisbeth, much appreciated). Regards ed

Hi Ed,

Sorry for taking so long to answer your questions.

I didn't order online. I ordered via the telephone in order that I could also have a chat with Shaun Williams.

It took Shaun about 10 days to get the kits together, he's a one man band so it's inevitable you'll face a bit of a wait though it shouldn't be more than 2 weeks.

Let me know if you order a kit as I've got some nifty little tweaks which are cheap to do when you're bulding the amp.

Regards

Mike.

 

[eddy]

Hi Mike,

I went ahead and ordered the amp, psu and some other bits and pieces last night using the online ordering system. Seemed to go smoothly but haven't received any email confirmation yet (although I didn't really expect to as it was out of hours).

10 days sounds more than reasonable, I really just wanted some frame of reference to stop me getting impatient.

Any tips/tweaks you have to aid construction or avoid potential disaster would be greatly appreciated.

Thanks again.

Regards

ed

 

[PinkFloyd]

Quote:

Originally posted by eddy Hi Mike, I went ahead and ordered the amp, psu and some other bits and pieces last night using the online ordering system. Seemed to go smoothly but haven't received any email confirmation yet (although I didn't really expect to as it was out of hours). 10 days sounds more than reasonable, I really just wanted some frame of reference to stop me getting impatient. Any tips/tweaks you have to aid construction or avoid potential disaster would be greatly appreciated. Thanks again. Regards ed

Hi Ed,

I'm certain Shaun will confirm your order very soon and there is no need to worry. I'm going to build a kit for a fellow Head-fi member and he ordered it about 10 days ago. it's due to be sent tomorrow so I'd reckon on between 7 - 10 days for it to arrive before getting impatient

The kit is pretty easy to build and the instructions are not bad but they do have their moments where you wonder what they are referring to but, on the whole, they are very good. If you run into bits you are not sure of then feel free to e-mail me and I'll help you out.

The most confusing part was with the 14 zero ohm resistors.... the manual says "fit a total of 14 zero ohm resistors in the component positions marked with a straight line" you will notice that there are only 12 component positions marked with a straight line leaving you with 2 spare resistors. These link across the two "A" component positions. The markings are A B A B fit them across the 2 "A" positions.

Apart from that it is pretty plain sailing.

All the best.

Mike.

 

[eddy]

Quote:

Hi Ed, I'm certain Shaun will confirm your order very soon and there is no need to worry. I'm going to build a kit for a fellow Head-fi member and he ordered it about 10 days ago. it's due to be sent tomorrow so I'd reckon on between 7 - 10 days for it to arrive before getting impatient The kit is pretty easy to build and the instructions are not bad but they do have their moments where you wonder what they are referring to but, on the whole, they are very good. If you run into bits you are not sure of then feel free to e-mail me and I'll help you out. The most confusing part was with the 14 zero ohm resistors.... the manual says "fit a total of 14 zero ohm resistors in the component positions marked with a straight line" you will notice that there are only 12 component positions marked with a straight line leaving you with 2 spare resistors. These link across the two "A" component positions. The markings are A B A B fit them across the 2 "A" positions. Apart from that it is pretty plain sailing. All the best. Mike.

Hi Mike,

Thanks for the handy tip about the reisistors, it will almost certainly avoid much frantic panicing and confusion at a later date. Thanks for the offer of some email support in case of a DIY amp emergency, much appreciated.

I am eagerly awaiting the delivery of my kit, can't wait to get started

Anyway, thanks again for your help.

All the best.

ed

 

[PinkFloyd]

I'm about to finalise this amp and, since my last post, have removed the balance control, tried a load of direct drop in op amps, tried a few different varieties of capacitor and am now content that the tweaks have made a big difference and will now give the amp a prolonged listening session.

I'm building another kit for a fellow head-fi member next week and will give my full appraisal after I have completed his amp.

Initial listening suggests that this is truly a very high quality piece of equipment, there is nothing in the shops that I have heard that is better than it.

I don't want to give my final opinion until I am totally sure the amp (with all the latest tweaks) is fully burnt in. I'm confident that when get down to some serious listening that this amp will blow the pants off any of the commercially available UK amps.

It is so "difficult" to judge which op amp sounds "best" in the circuit when I have 11 to evaluate but I'm slowly but surely reaching a conclusion!

I'll give a full report on the Chiarra / Andante kit shortly and will upload my findings and details of tweaks to http://freespace.virgin.net/rock.grotto/index2.htm

As it stands though ........ I have no hesitation in recommending the Chiarra / Andante kits from Williams Hart Electronics. A dedicated PSU and amp kit for £200 that sounds superb into the bargain..... it's got to be worth taking the time to build

I'll give a full review shortly.

Pinkie.

 

[wordsworth]

Can't wait to hear your review mike. It is also good to see you can still get a bargin in the UK

Mark