Jaycar Headphone Amp Kit

[marcm09]

Lovely work on this amp guys, wonder how it compares in stock form to a v2 xcan ? Also wonder how it will compare once we all fit a fix for the perfect mods ?

[Deleted]

For any of the technical types who are able to etch and construct a JLH PSU addon PCB ,
I highly recommend this addition. I have recently been able to reference against an otherwise identical modified unit, except for the JLH PSU addon between the voltage regulators and the main PCB. The JLH version has an "awesome" bottom end when working into my Sony Headphones, you can really feel the low end in your head on quite a bit of material. Interestingly, not only is the soundstage better, with extra detail, but at the same time it is sweeter sounding, and sibilance is less obvious on much material at the same time.
The present drawback, is that the extra space necessary to include the JLH, may necessitate a larger case. Allan (Pagan) is currently working on a much smaller PCB for the JLH.
SandyK
P.S.
The ATH W1000 haven't had much use since modifying this HA. The old 32 ohm Sony headphones now sound fabulous!

As always, though, this is subjective, and some people may not agree with my assessment.

[Will]

Hi Sandyk,

Very interested in this JLH PSU addon. Can you point me to a CCT diagram? I think I found a +ve rail version, but the search on the forum stops me going any further, for the -ve rail. (you need more than three letters to search!)

If Pagan is going to get the boards manufactured, I'll be interested.

I'll be ordering the Jaycar kit soon, so I going to have some electronics based fun, the first in a long, long time!

[Deleted]

Wilbur
The posted diagram should have the changes for the -VE rail version listed underneath.
Allan is away for a couple of weeks (working) and I am currently putting together his trial mini version, but I have found an error in the current limiter area of the PCB. I should be able to get it working without the limiter if the rest is O.K. We would like to get some made, but hope that another friend can use Protel to get a design that RCS Radio can make some from.
Have a look at rockgrotto.proboards39.com/v45index.cgi?board=q&action=display&thread=2068&page=3

[Deleted]

Miguel
I connect the JLH between the Jaycar KC5418 Dual regulated PSU kit's +-15V 3 pin connector, and the amplifiers power supply,3 pin connector terminals. I hope to try Allan Pagan's mini JLH PCB in the other SC Headphone Amplifier later today.
Alex

[Deleted]

I have just built a mini dual JLH on a much smaller PCB that was designed and made by
Allan (pagan) Unfortunately Allan wasn't able to put it together himself, as he is away working down Southern NSW for a couple of weeks. I tried it a few minutes ago in another modded SC headphone amplifier, that was identical in components to the posted design, except that it didn't previously have a JLH fitted.This PCB uses 2 x 2,200uF per supply rail instead of the 4 x 1,000uF of the larger version, due to space considerations. However, this amplifier now sounds virtually identical to the other amplifier.i.e. quite a large increase in performance.
The new PCB is actually slightly smaller than in the photo.

SandyK

[dc]

if you make PCBs i'd be interested

[Will]

Me too.

[Deleted]

if you make PCBs i'd be interested

dc and wilbur

The problem is coming up with artwork in a format that a PCB maker like RCS Radio can use. This present PCB has an error in the current limiter area, which luckily, isn't needed this time. When Allan does a little further refinement with this design, we will see if RCS is able to make boards from simple artwork, instead of Protel as normally required.
BTW, have either of you tried to make your own PCBs ? Allan uses a Laser printer, and the iron-on method, to create a PCB for etching and drilling. Another method, that I use occasionally, is positive artwork printed on a transparency sheet with an
IJ printer, then used with a photo sensitive PCB, and small desk fluoro lamp.
Alex

[dc]

When I was in school we etched our own PCBs using the transperancy + UV light box then into the hydrochloric acid

edit: I don't know a thing about reading schematics and making board layouts is the problem.

[Deleted]

dc
Do you have a PCB drill? The Jaycar PCB kit has a couple of photo boards and enough photo developer and etchant for a few boards, as well as a Dalo pen and ordinary blank PCB for making simple PCBs. Allan and myself can supply artwork that works for one off JLH PCBs. Allan's design is more compact, but needs him to make a minor correction to the current limiter (if used). Plug the cat.no. (below) into the Jaycar "search"
Alex
CAT. NO. HG9990 RRP $24.95
PCB ETCHING KIT
An ideal kit for anyone needing to etch a circuit board - complete with an assortment of double-sided copper boards, etchant, working bath and twee...more...
QTY
1+ $24.95
4+ $22.35
10+ $19.70

P.S. You don't need a UV lightbox for one offs. I use a small fluoro desk lamp hanging a couple of CMs above the transparency , which is on top of the photo sensitive board, and held in place by a piece of glass from a small picture frame sitting on top of the transparency. The only drawback is it takes about 15-20 minutes.
(The little desk fluoros also give off UV light) In fact, you can also use bright sunlight , although not much good at the moment!
Allan's iron -on way , using a Laser printer also results in pretty decent PCBs (below, before trimmed)

[Will]

Apr 17, 2008 8:22:23 GMT @sandyk said:

if you make PCBs i'd be interested

dc and wilbur

The problem is coming up with artwork in a format that a PCB maker like RCS Radio can use. This present PCB has an error in the current limiter area, which luckily, isn't needed this time. When Allan does a little further refinement with this design, we will see if RCS is able to make boards from simple artwork, instead of Protel as normally required.
BTW, have either of you tried to make your own PCBs ? Allan uses a Laser printer, and the iron-on method, to create a PCB for etching and dril... *Snip*

Good Idea, especially after reading the post to DC that followed. I last made boards during my apprenticeship (I was 18 then, now 36), so I'd be a bit rusty. I'll come back to this and have a go.

[kittenyberk]

Anyone know how long the shipping takes from jaycar?

[Deleted]

Miguel
Anything is possible . Mike or Leo undoubtedly could. I wouldn't even attempt it.
Wilbur
As a matter of interest, the larger size JLH shown in the X-DAC V3 PSU photo , used one of the 2 photo sensitive boards from that kit. One of the boards was the exact size needed.
Those PCB kits aren't exclusive to Jaycar either.
BTW, the trick with those photo sensitive boards is to use only a small amount of developer, and add extra as needed. When the pattern starts to appear, you have to be quick removing the PCB from the solution,or the pattern washes away. That's another good reason for no more developer in the water than necessary.
Alex

[Deleted]

Anyone know how long the shipping takes from jaycar?

kittenyberk
You would have to ask Mike that one.
Alex

[Deleted]

Yesterday (Sunday) I took the modded SC headphone amplifier with mini JLH to a friend's place.As he has only just moved there
he had only a couple of CDs to use( the rest of his gear is still in storage). The HA was fed from the Oppo and his modded X-DAC V3, which supplied the signal for both the SC HA using my Sony Headphones,and his Stax setup using Stax Driver (SRM313)
Although fuddy duddy material, the SC HA and Sony
MDR- CD780Headphones, ate for breakfast, the Stax setup
I never fully realised how mediocre my old Stax setup really was via that driver.
Far better 3D, vastly better separation and delicacy from the JLHd SC HA.
Chalk and Cheese !
The only negative comment from my friend, was that on one section of material, that it was almost like dual mono. i.e Highly separated. Geoff is a rabid Stax lover, but he did ask how much the Sony Headphones cost.
The sound may have been TOO detailed with headphones like the ATH W1000.
SandyK

[dc]

what Stax phones?

I find that really hard to believe.

I don't know how good the modded jaycar is or how bad the SRM313 is.

I find it hard to believe the dynamic setup was more detailed than the electrostatics.

Sure, there are many things that dynamics do better and are preferable to electrostatics, which is the reason I still have dynamics (and it's still a fair bit larger than my electrostatics gear, cost aside) but details is one area where electrostats have always excelled ahead of dynamics.

[Deleted]

dc
I forget the model of the Stax headphones, but I originally bought them new, about 3 years ago with the SRM313 driver. There was nothing wrong with the headphones, as they sounded fabulous ( except for 2dB rolloff below about 150HZ) when used with my 15W/Ch Class A amplifier into a STAX transformer. My friend Geoff bought me a new pair of ATH W1000 in exchange for those Headphones and driver.
I believe the vastly better channel separation due to the JLH also played a part.
Alex

[dc]

I imagine it would have been the SR-303 (off green colour) that would have been sold with the SRM-313 as the Stax SRS-3030 "Classic" system.

You make me very curious about this JLH board now. It may not be that Stax is bad, but that your modded amp is exceedingly good. Don't know a thing about the Sony headphones though =\

[Deleted]

dc
I tried it connected to the modded XDAC V3 via Oppo this morning, in a comparison with my Class A preamp's headphone output. It was very good indeed, but female vocals were a smidgin less smooth than the preamp. It had that slight LM4562 character that a couple of people have remarked about in the forums. Where it REALLY shines, is when connected to analogue out of my X-FI sound card (with OPA2134 in lieu 4560 (?) ) BUT using Creative Media Source Player, (which I think uses ASIO drivers and bypasses Windows Mixer) and playing tracks ripped with EAC from the HDD.
Alex

[Deleted]

For anybody contemplating constructing this amplifier + mini JLH ,
the recommended size case is as attached. There isn't a great deal of extra room with the case, and the main PCB will need to have very little clearance from the rear panel, as well as being as far over to the RHS as possible. The information is from the Altronics website, although many suppliers will have a similar or identical case.
SandyK


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[PinkFloyd]

Alex.... I hope to spend some quality time with this amp next week when I'm cleaning my system out (my organs, not my sound systems) and will be rejoining this thread with vigour.

Did you lose the inductors? I can't see any real advantages of keeping them in circuit and better out than in IMO...... your comments appreciated.

[Deleted]

Mike
My current version is on page 3 of this thread. The ouput resistor should be 68 ohms, not 47 as shown.With the JLH, there is no need to change the 470uF filter capacitors either. An earlier version using the RLC was compared with it, and the earlier version has since been modified and is now virtually identical , except for using one of Allan's mini JLH PCBs. When using the JLH, bypassing the fuses with a link is an advantage, but the output's emitter resistors should be .5W , not 1W.
The LM4562 is I think the key to the performance, but it would be worthwhile using a good quality DIL socket for opamp rolling.
I will be remaking the whole lot in a new smaller case as shown in my last posting, but with the addition of a 50K 23 position attenuator made from a kit that I ordered yesterday from DIY Fidelity. My preferred headphone listening mode with headphones is now from EAC ripped .wav files to PC analogue out, but using the slightly modded soundcard's Creative Media Source player, which uses ASIO drivers and bypassses the Microsoft mixer. I am surprised that the PC route is capable of such high performance.

As Mike mentioned elsewhere, no amplifier and headphone combination will suit everybody, so at least 2 pairs of different headphones is an advantage.

Alex

[leo]

I'm surprised others have not brought one of these amps yet, make an ideal first build project, cheap to boot!

[Deleted]

Leo
From memory there are 3 members who have told me they have ordered the kits, and asked for the colour photos of the original article to assist with construction. I imagine that some other members are waiting to see how well Mike can make it perform before jumping in ? Several members have also enquired about JLH PCBs, which at the present time, would have to be etched by the constructor. I hope that Allan's latest mini JLH PCB, when finalised , may be able to be made in quantity by RCS Radio. No promises though !
Alex