Review: Twinkle headphone Amp DIY kit (with pics)

[loop_ 0]

 

Posting a review of this kit. The main purpose is to encourage those who are interested into going into audio diy but think that they don't possess the requisite skills. It's not that difficult really, if you start with the right kit. The main problem I faced was the lack of good safety practices i.e. I let electric current pass through me more than once....

 

I got introduced to audio DIY just under a year ago, when I bought a zen headphone amp from Digi, and got Huangyong to change the caps for me. Thanks to huangyong, I have lost a lot of money since.... =(

 

Anyway, I was an arts student in JC, and only have sec 4 physics skills, which is nonsense. I still don't know what current, voltage and wattage means, but I can do a proper solder. Frankly, that, and some guts, is all you need, plus lots of ppl on MSN whom you can bug. haha

 

INFO

 

I bought the kit from erji.net from Mr. Dou. http://www.erji.net/read.php?tid=260272&fpage=1

 

Basically, this is s a 3 channel design (you can make it 2 only as well) which employs an OPAMP plus Diamond buffer, a little similar to the PPA. The kit comes with everything you'll need to set the boards up except for the opamps. It also comes with a manual, in chinese, on how to set this thing up. The manual is a great help (it's in .pdf on the forum link), but is in chinese. Reading a chinese storybook is one thing, reading a chinese technical manual is quite another!

 

You'll still need to get your own casing, toroid, and other stuff for your case like switches and volume knob etc. Total cost for the kit including shipping (shared EMS with 2 others to Singapore) was about 75-80sgd.

 

I bought my casing from www.hifidiy.net. Also bought a 50K alps pot, and a great multimeter (the UT52 for $23sgd only) The total cost for this purchase was high, because of the shipping ($40, not EMS). The casing is very heavy, but well built.

 

All in all, the buying experience from Mr. Dou and hifidiy was very pleasant. Shipping was prompt and there was communication throughout. The only problem was that I paid hifidiy using western union, and the retailer was not familiar with it. However, he still bothered to take 2-3 trips to the post office and we finally figured it out. He also shipped me a 100k alps pot erroneously, but rectified it immediately by sending me a 50K pot. So I got a free 100K pot!

 

SETUP

 

Setting the twinkle up was very easy. I just took care to solder everything where it should be. In particular, Mr. Dou made an error in his design, and one cap was drawn in the opposite direction in the PCB. However, ample warning was given in the manual.

 

After completing each channel, you just need to take 2 measurements. The first one is for the voltage, which requires adjusting to 12-18V, depending on your preference and opamp. There are also 3 jumpers which allow you to disconnect the power supply from the amp, for setup purposes. Mr. Dou also includes a protection board for each channel, which reduces the power supplied to only 0.1V if there are any problems detected. It will light up if there is a problem. However, I got an faulty one which lit up for no reason, had a real tough time yanking it out.

 

 

Second one is for the output DC offset. Make sure it's below a certain value, and one channel is done!

 

 

When they work, all LEDs light up.

 

 

The main problem I faced was hum due to poor grounding. One reason could be that the pcbs have one mounting hole connected to the ground, and I screwed it in so tight i can't take it out now to try and isolate it. Anyway I played around and now the hum is only noticeable on my w1000 (not on my hd600 and hf-1), and only if I really pay attention to it. For example, if I plug my w1000 in and out and carefully listen for the difference, it's discernable. Otherwised, it's very quiet. Completely black quiet on my other 2 phones.

 

At all times when I faced problems, I just asked Mr. Dou on MSN and other experienced diyers like squalle, huangyong, and a friend from China. Be shameless, just keep disturbing them. For example, I bugged huangyong to teach me how to diy an LED using a resistor and diode. Had to ask him what direction, what value, what is an anode and a cathode...

 

SOUND

 

My source is a 4g ipod modded by www.redwineaudio.com. I use a hf-1, W1000, and HD600 with equinox cable. I am using opa627s.

 

I have been listening to this amp for about 2 weeks now. Its strengths lie in its separation, detail and bass control. However, its main weakness is that its highs can be a little weak and shrill at times. Tonally, its closer to clean and musical rather than warm and fat. Very good contrast with my zen, which has a much smoother sound, but has less details and poorer soundstaging. At this price point, you can't expect perfection.

 

I have tried to tame the highs by changing my rca-mini cable to a copper one, and changing some of the caps to a WIMA cap and blackgates. Much happier now.

 

 

*edit: After another 2 weeks of solid, daily listening, I'm really amazed by this amp. It is just so different from all the amps I own and have heard in that the soundstage is so big! Everything sounds so far away. This is not something everyone likes though..could be a little too distant for some

 

To sidetrack a little, I bought my cables (internal and RCA-mini) from SimlimSquare, UPOCC copper, at

 

$4.50 a metre. Braided them myself, copying homegrownaudio's 4 braid. Quite fun.

 

The main thing, though, is that although I like my zen alot (it has a more serious noise issue though), I keep returning to the twinkle. Why? Because I built it all by myself. Every solder is made by me (except the protection board), and I wired and drilled everything. There is just so much satisfaction listening out of something you made yourself. I even find myself staring at the LED because I made it myself. Eye pain...

 

All in all, if you're interested in starting something for kicks, the twinkle is easy to recommend. It is fairly easy to build, and provides great music for the price. Make sure you never touch anything with your bare hands when it's powered though...

 

Hansel

Edited September 10, 2006 by loop_

[jasonhanjk 0]

You can try reduce the hum be removing the transformer and rectifier away from you amp.

 

Edit: Why is your poly cap connecting to one of your RCA?

This configuration doesn't make sense.

Edited September 3, 2006 by jasonhanjk

[loop_ 0]

tried already leh..no use...

 

The poly cap is meant to be some kind of gound loop breaker. I connected it to the casing from the rca. Supposed to help reduce the hum. I think it would be more effective if the PCB ground wasn't connected to the casing. For some reason, it helps though...or maybe it's just some placebo. But really, the hum is not something that bothers me...can't be heard 99% of the time.

[jasonhanjk 0]

How about regrounding the cap to another part of the casing?

You can also try adding 10nF poly cap accross your diode.

[loop_ 0]

which diode? for the LED one?

 

thanks for the advice man. I will try it one day. I've worked and done troubleshooting for more than 1 week already...and school is starting!

 

Bo lat liao.

 

 

[jasonhanjk 0]

4 on each board. Total 12. May or may not work.

[gfgfmoses 0]

thanks for the review. mine is not started yet, need to bother u and huangyong for all the diy things later regularly then.

[heady 0]

Well done, loop. Good job. One day, we all must have a diy meet to bring our amps for listening comparisons!

[loop_ 0]

Thanks for the encouragement! Hope to bring this amp for the next meet, if there's one, at the end of the year...Heady, I wonder how the twinkle sounds compared to your PPA...

 

Top-Gun, the kit doesn't come with the casing. I bought the casing from here: http://shop.hifidiy.net/product/46.htm

 

Comes with all parts, switches, knob, IEC socket, but not the RCA jacks

Edited September 5, 2006 by loop_

[huangyong 0]

Just tried the twinkle 3 days ago, didn't have much time to post my impression of it till now. First of all, i must congratulate loop for his great work, the amp is a masterpiece, on par with amp made by digi01,firefox or even better I would say. and this is only his SECOND DIY project!!!! hooray, you made it!!!

 

The actual amp looks better than the one you see on the photo. The case is fantastic!!, only if it costs cheaper..and i will get it for all my DIY amps. The finish of the aluminium face plate is smooth and not much difference from the commercial amp out there. To open the top plate, simple use allen key and apply little bit of force and the screw comes out very easily.

 

Look at the inside.. WoW... neat and tidy, and look closer at the board, fainted@$%$^, he used flux remover. The board looks so clean that as if it was soldered by machine.

 

Some additional info i got from the designer:

The amp is actually inspired by PPA, quite similar in term of circuit concept. The major imorovement is this amp employs a constant current source in the output BJT buffer, hopefully it improves the sound (in theory it does). Another improvement is the individual supply for each channel, and the supply circuit is high speed shunt type discrete regulator. This is somehting unique among Chinese DIYers, they somehow prefer this over IC type regulator. On the other side, the westerners usually like to use IC type regulators in their amp, e.g Corda, Gilmore,PPA.

 

SOUND TEST:

In This sound test, my primary objective is to find out whether i should build this amp for my current setups. I already own a few DIY amps, and this one defintely will take me sometime. As a wise investor of time, I need to test first before I build the amp.

 

Equipment:

Headphones: HD600 + Equinox, pre2006 DT880 (old flagship)

Source:Modded Ipod, Apple PowerBook G4

RCA to mini Cable: loop's (cost him $46), mine (cost me $8)

AMP: 1. Twinkle with 3 OPA627AP

2. My own amp (own design)

Left right channel using OP637BP with stacked BUF634

Virtual ground opa2227

Ground channel with OPA627BP with Class A MOSFET

Virtual ground opa134

 

RESULT:

 

DT880 with Twinkle with Modded Ipod

WOw.. very huge soundstage, it reminds me of AKG 501. It makes me feel like I am in a big opera house, and I no longer feel like I am wearing headphopne.. I was listen to an orchestra piece, sitting at the back of the audience sits and listening to the music. The detail is superb and sound is very clean, studio like effect. I could hear most of the background details, too analytical that sometimes annoying. Imaging is its another strength, I can pin point where the sounds comes from, and the depth is there.

 

The down side is the paring is not the match make in heaven. Both DT880 and Twinkle have flat and clean sound, when they work together, the sound lacks of tonal quality, lacks of authority, lacks musical. Big soundtage and details didn't help much when it comes to vocal. OMG, vocal suppose to convey the emotion of the song, but it wasn't there. I didn't enjoy it at all.

 

Conclusion: DT880 + Twinkle is for Studio use

 

DT880 with my amp with Modded Ipod

Due to the amp is designed and built by me, I will defend it till death, for my EGO is big when it comes to DIY stuff.. haha... I will surely say my amp is good .. thus, let me quote wad loop said.

 

1. the 2 amps just sound different.

2. my amp sounds like ZEN, more warmth

3. we both agree that my amp is better in term of tonal quality but lacks details compared to Twinkle.

 

Conclusion: DT880+my amp is more enjoyable (to me)

 

 

However, the Twinkle sounds superb with HD600, dunno why..

 

So, I will not build this Twinkle unless I got a HD600 or HD650. Thus I will let Twinkle go, anyone needs it just tell me. Thanks....

 

Good night!!

 

 

[loop_ 0]

Just tried the twinkle 3 days ago, didn't have much time to post my impression of it till now. First of all, i must congratulate loop for his great work, the amp is a masterpiece, on par with amp made by digi01,firefox or even better I would say. and this is only his SECOND DIY project!!!! hooray, you made it!!!

 

 

thanks for the encouragement..but don't need to say until like that la...how to compare with those pros? I'm just doing soldering and wiring..no design..

[RancidM 0]

Is a damm sexy looking bit of kit for sure.

[loop_ 0]

i have the ipod!

 

 

but sadly, i just sent it back 2 days ago for a repair. For some reason it picks up some background hiss when the volume of the amp is at max...then after that i'm going overseas...maybe in December..

[huangyong 0]

wad!!! sent back for repair?? then wad u use as source then???!!

also, loop, please write your impression when doing AB test with my amp..hehe

[loop_ 0]

wad!!! sent back for repair?? then wad u use as source then???!!

also, loop, please write your impression when doing AB test with my amp..hehe

 

 

using a sony D321 PCDP line out now...not bad..but I still miss my ipod..

 

 

amps are such subjective things. Put it this way. As you mentioned, for DT880, I like your amp, but for HD600, I like the twinkle...They are very different, the twinkle is detailed and faster, while Huangyong's own design (that he forgot incidentally...) is slower and more lush sounding.

 

Sadly, I didn't listen to his amp enough to have a real impression...i'm too obsessed with the twinkle. hahah