..:: ZOMBiE Destinee ::..

Sunday, September 07, 2008
Transposted: RSA Tomahawk Portable Headamp
[ZOMBiE CyGiG] ranted at 9:33 AM --- Post#2112919237293408688

The following are quoted from Wenze's blog.

>>QUOTE START<<

After getting to see a picture of the innards in real life up close, I knew I just had to get the picture off the net.

And get it I did:

Source: http://hobbyroom.blog.so-net.ne.jp/2007-06-05

Erm, that's it? And this thing costs >$500? WTF?

2 x 1.5V batteries, not a lot of power for the op-amp. At least it's splitted into + and - rails.

A 15000uf cap acting as power reservoir to make up for the batteries that will undergo too much strain by the power load. But big capacity + low rated voltage = slow performance so there's a trade-off. Hopefully this is the correct size, but the Predator also uses the same cap while the Hornet uses a 15000uf @ 10V, coincidence or do they just have too much of this?

>>QUOTE END<<

Sorry, i dun have a proper quoting css implemented on my blog. The Toma we tested were Iittoo's.

To add on, the allen screws were badly rusted. Battery contacts need several attempt to get it working. The sound signature seems to from Analogue Devices (or BB? Not quite likely). A search at AD's website for low power opamp that can take +-1.2V should not be far from whats under the paint.

He came to RMA a cable from me, but after the three of us (me, wenze, Iittoo) fiddle around with out test equipment, we found out its due to the poor connection of the CrossRoad dock. Nothing is wrong with the rest of the cables or equipment.

D2 > cable > toma/mini3 - OK
iPod head out > cable > toma/mini3 - OK
iPod > CrossRoad Dock > Cable > toma/mini3 - NOT OK!!!

The poor connection caused static and 'one side no sound' syndrome. By tilting and fidgeting and dock, at times we can get a good connection, but most of the time not.

I dunno if its the ipod or its the dock, but the physical connection between the both is utmost unstable. With a bit of strength, u can literally break the dock off from ipod's connecting bus. When they are connected, u can jerk the dock up down left right, and it has very little resistance.

We took a closer inspection at his dock, there were two mechanical teeth protruding on the sides, when the side button are pressed, the teeth should go back in, and when released, they are suppose to come out to hook onto the ledges on the ipod connection bus. But one of the teeth seemed to be semi stuck, its halfway protruded only when the buttons are release. Isit poor QC or isit meant to be liddat? The later seemed not to be so, as u can search for pics on google, the pins on both left and right seemed to be of the same protruding length.

UPDATE: After asking alvin, it seems that even on other LOD, connection problem is still evident. But my guess is a good dock may reduce the symptoms of poor connection.

Ittoo was rather fed up, so i recommended him either
1. Get his dock RMA from where he bought it
2. Get a sendstation dock, which seems much better. There is a shop in singapore retailing it so can go down and try try b4 buy.
3. DUN USE iPOD!

He was telling me he would prolly sell his ipod for a D2, after i let him test my rig. D2 (at vol 34) > SilverMAX Ultra > Mini3 OPA2134 > his own SuperFi 5. I got a very positive respond of the mini3 from him also. Esp the OPA2134 version.

D2 do not perform well at vol 49, very fatiguing. Wenze was suggesting that it may be technically line out at vol 49, but it would be challenging in terms of power for D2. 49 is the value suggested by the Cowon technical team IIRC. 34 was suggested by some iaudiophile.net forum members. 34 may be further way from line out, but no power problem. Does it mean at 34, it distorts badly due to double amping? I did a test on a handful of peepz, with relatively trained ears. None could hear distortions at 34. Iittoo and wk prefer 34 to 49.

Anyway, in the end i still RMA a cable for him. Though the cable he was having is absolutely alright. I let him choose one cable that heng heng the mechanical tension when bent and put in his hippocase is able to hold the dock in place. He choose one, which initially worked, but as expected, the problem came back soon when the position of the devices change and the dock's connection problem resurface. Well but at least he got his cable upgraded from me for free. Tri braid to quad braid silver. Haha.

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