Jaycar Headphone Amp Kit

[rossman]

admin said:

leo said:

Excellent stuff! looks bob on in that Maplins case too
I'd imagine that traffo your using now is going to be better than a toroidal anyway when used in the same case

It's light mate and will be heading your way shortly if you dont mind paying £5 return delivery? I think you'll be VERY impressed with this guy BTW I detest toroidals.

errr, whats a traffo, where can I get one, how much should it cost and does that mean I can get away without bringing a toroidal back with me?

[Deleted]

rossman
15-0-15V 30VA Toroidal transformers should be readily available in the U.K from Antrim Transformers and electronics suppliers.They cost between AU$22-30 here. Alternatively, you could do the same as Mike did in his photos, perhaps even buying one from Mike ?
SandyK

P.S. Forget Maplin !
Also, Jaycar now only stock 15-0-15 20VA
Toroidal Transformers. The .66Amps rating for each winding is more than adequate. (The original 30VA unit supplied the preamplifier too, as well as 5V supply for remote control and relays)

[dc]

sandyk said:

dc
The present case is too big. But it sits O.K. on top of the PC.
I have asked one of my friends, who also uses a JLH board in his preamp, if he would use his Protel program to come up with a better PCB layout for the JLH board than the current (newer) version, so that we can get some made at RCS Radio. So far he hasn't got around to it. Pagan (Allan) has come up with a REALLY small JLH layout that works,but it isn't able to be used for PCB making by a PCB manufacturer. Several people have asked for PCBs , but it is very time consuming (and fiddly) to make more than the odd one for yourself. As Allan and Leo, can confirm, these JLH boards really do make worthwhile improvements to power supplies for DACs, amplifiers, etc.
Alex

How does the JLH compare with power supplies like Tangent's STEPS and AMB's Sigma 11?

[Deleted]

dc
The John Linsley Hood PSU Add on, is not actually a PSU. It is not voltage specific, but could be described as a "noise and ripple eater" with a very low output impedance over a far greater frequency range than a typical voltage regulator.IMHO, It will easily outperform the Tangent supply, but I don't have enough information about the Sigma to give a definite answer.I do expect that it would, however.The JLH can be used with any regulated voltage supply up to 24V or more without any modifications. In fact, Pagan (Allan) has a modified JLH working at + and -55V with a 100W /Ch. Power amplifier's front end supply. If you have a look at my recent post in the Extreme mods to the X-DAC V3 you will see that it virtually eliminated any expected likely improvements to be gained by fitting Super Regulators, to the various sections of the X-DAC. And that is without even taking the cover off the modded X-DAC !
Alex

[dc]

So if I'm reading that correctly, it sits between the outputs of the PSU and the input of whatever device is being powered, and acts like a filter?

My steps is currently outputting about 34.5v (which is 33v at the opamp socket for all the opamps I use that are max 18+/-)

[insomniac]

Check this out...

From: www.jaycar.com.au/

Stereo Headphone Distribution Amplifier Kit $29.95

Headphone Amplifier Power Supply Kit $17.95
----------
$47.90
approx £22.13


From: www.jaycarelectronics.co.uk

Stereo Headphone Distribution Amplifier Kit £8.75

Headphone Amplifier Power Supply Kit £5.25
----------
£14.00
approx $30.29

Even with the £5 UK delivery charge its still cheaper to buy this here.
Good to see nice prices like this in the UK...Maplins must be sharting
themselves

[Deleted]

insomniac
It's still coming from DownUnder. Just a freecall line from U.K. to Jaycar HQ in Sydney, and U.K. or US.A. pricing available online. Heavier items like toroidal transformers are best bought locally.
SandyK

[insomniac]

Sandy, I know it's coming from Oz but what I was hinting at was for maybe rossman and others, who might pick this up whilst on holiday over there. Perhaps some folk would rather pick it up from a Jaycar store and add a bit of history to the amp...i.e.

Nice Amp...did you build it?

Yes...I personally carried the components thousands of miles from Australia...blah..blah.

Anyhow it's a great deal either way...
Thanks Sandyk and Mike for introducing it to the Rock Grotto masses

[Deleted]

So if I'm reading that correctly, it sits between the outputs of the PSU and the input of whatever device is being powered, and acts like a filter?

dc
Yes. If it's current limiter is left in , it usually drops the input voltage by around 300-500mV to each voltage rail.
With the current limiter bypassed, and using LM317/LM337 or LM78xx/LM79xx regulators to supply it, it relies on the startup current limiting of the Voltage Regulator. In that case, there is an even lower output impedance, start up time is less than a second, instead of several seconds with the current limiter in circuit, AND the output voltage is the same as it's input voltage.
Alex

[PinkFloyd]

insomniac said:

Check this out...

From: www.jaycar.com.au/

Stereo Headphone Distribution Amplifier Kit $29.95

Headphone Amplifier Power Supply Kit $17.95
----------
$47.90
approx £22.13


From: www.jaycarelectronics.co.uk

Stereo Headphone Distribution Amplifier Kit £8.75

Headphone Amplifier Power Supply Kit £5.25
----------
£14.00
approx $30.29

Even with the £5 UK delivery charge its still cheaper to buy this here.
Good to see nice prices like this in the UK...Maplins must be sharting
themselves

You just can't "not" order one at these prices.... £19 "shipped" it just has to be the audio bargain of the century and great fun putting it all together too

[Deleted]

Miguel
You would also need a suitable .5A fuse for the holder. The other unit would remove the need for a front panel on/off switch, but wouldn't be my preferred personal choice. Don't forget that your transformer has to suit your lower voltage mains supply. Perhaps Mike's transformers are able to be used with either mains supply ? Mike has a lot more experience than me with transformers that have primary windings suitable for both the U.S. and U.K. markets, as has Rick.
Alex

[leo]

I always found those filtered IEC sockets make the sound worse tbh

[Deleted]

Miguel
Yes, that would be better. It also has provision for a fuse, most likely an M205 type fuse. (Use .5A for a typical 30VA toroidal transformer) If I am not mistaken, it also has an inbuilt mains filter. Do you need the extra bulk of this unit ?
Alex

[leo]

I'd just go for a standard fused IEC inlet Miguel, like those ones you posted but without the metal box containing the mains filter
The ones with a switch on may makes things a little easier for you , just saves wiring a separate switch on the front or back

[Deleted]

The ones with a switch on may makes things a little easier for you , just saves wiring a separate switch on the front or back

Miguel
The only drawback then is that you will have to wire in one of those fuses. An assorted pack of small lengths of heatshrink tubing would be useful too, to insulate the fuse and other mains terminals.
Alex

[PinkFloyd]

sandyk said:

Miguel
You would also need a suitable .5A fuse for the holder. The other unit would remove the need for a front panel on/off switch, but wouldn't be my preferred personal choice. Don't forget that your transformer has to suit your lower voltage mains supply. Perhaps Mike's transformers are able to be used with either mains supply ? Mike has a lot more experience than me with transformers that have primary windings suitable for both the U.S. and U.K. markets, as has Rick.
Alex

Yes Alex,

They can be hooked up (at the primary) for either 115V or 230V thus:




The secondary wiring is obviously the same whether 115V or 230V with the centre jumper being 0V, the outer ones 12V so..... 12V - 0V - 12V. This particular batch I have never used in the Little Pinkie as they all measure around 15.9V under no load so absolutely ideal for the Jaycar project..... compact too and can be reverse mounted and secured to the chassis with self tappers into the 4 slots on the encapsulated.

[Deleted]

Miguel
Why not wait until Mike has had a chance to try some mods before deciding ?
Although cheap, it needs to offer performance better than what a lot of people are already using, unless they just want to learn how to put together a kit for the learning process, and the satisfaction obtained by building something themselves, with their own personal touches added.
Besides, I would hate people to post "SandyK recommended this kit, and it sounds shite "
Alex

[XTRProf]

Apr 6, 2008 23:38:12 GMT leo said:

I always found those filtered IEC sockets make the sound worse tbh

Err, unless is way overated like what I like to do. But even in that mode, I prefer without to keep to KISS for the best sound.

[PinkFloyd]

Apr 7, 2008 22:30:24 GMT mrarroyo said:

Mike, have you given any thought about puting together a "kit" for the Jaycar? It would include everything someone like me would need in addition to the two kits sold by Jaycar.

I would think that others besides my self would be interested.

erm..................................... the Jaycar "is" a kit Miguel.

[rossman]

Apr 7, 2008 23:17:01 GMT @sandyk said:

Miguel
Why not wait until Mike has had a chance to try some mods before deciding ?
Although cheap, it needs to offer performance better than what a lot of people are already using, unless they just want to learn how to put together a kit for the learning process, and the satisfaction obtained by building something themselves, with their own personal touches added.
Besides, I would hate people to post "SandyK recommended this kit, and it sounds shite "
Alex

I would be using this kit as you have described above, to learn how to put a kit together. I would also want it to sound good. But if I didn't I wouldn't blame you Alex. For what it is going to cost it must be worth the price for the experience gained for a novice anyway. Anything better would be a bonus as far as I am concerned.

[insomniac]

Apr 8, 2008 12:59:44 GMT PinkFloyd said:

Apr 7, 2008 22:30:24 GMT mrarroyo said:

Mike, have you given any thought about puting together a "kit" for the Jaycar? It would include everything someone like me would need in addition to the two kits sold by Jaycar.

I would think that others besides my self would be interested.

erm..................................... the Jaycar "is" a kit Miguel.

Perhaps Miguel is inquiring about the jaycar pimping kit......the "Turbo" add-on kit. Maybe IEC inlet, Pot, upgraded Caps and other selected Pink tweaks in there.

Will you be doing one of these Mike?

[leo]

Maybe worth doing a full BOM for this amp so it helps everybody wanting to have a bash at one.

I'll be honest chaps although I've not heard or built this amp looking at the circuit I'd say this thing should sound rather good once its been fully modified, the circuit isn't hugely different from some commercial made pricey units

[Deleted]

Leo
It's worth noting that as the 2 kits would have to come from Jaycar, the rest of the components could also come from Jaycar at the same time. Their prices are obviously far better than U.K. prices anyway. An exception would be the transformer, which is possibly better sourced either locally, or from Mike. Mike may already have a good supply of these additional components, or is readily able to obtain them in the quantities required (like case etc). Assuming he is willing to do this !
Alex

[Deleted]

If any member purchases the 2 Jaycar kits to make the amplifier, send me a PM, and I will email scanned quality colour copies of the relevant parts of the original article that the kits are based on. Jaycar does of course provide B &W photocopies with the kits.
SandyK

[Deleted]

Miguel
I think that Leo is already working on a BOM. You can't really come up with a complete BOM until the amplifier has taken it's final shape. It will also vary with the type of transformer used, just to give one example. Also there is whether you want to get a case from Jaycar as well, or order one locally that may be more visually appealing.
Why don't you contact Mike, and see if he is able to not only supply the transformer shown in his photos, but the perfboard and other components associated with it ? Mike may even be able to sell that section already put together for a small additional fee. Perhaps in your special case, just for the cost of the components ?


Alex