heady

Shhh.... tropical, that's EXACTLY what my friend said to me when he egged me to put the ad. We married people have to get permission to spend big bucks like that you know. Anyway, one step at a time. So first step first. I paid $1300 for the Fuji S1Pro two years ago and really didn't make that much use of it, so I must really think very hard to splurge on a DSLR again. Any of you D70 people want to upgrade to D2?? I'm using an Olympus 5060 most of the time now, easier to carry.

I feel digital cams are less forgiving than slides which are already less forgiving than colour negatives. I grew up with slide films and it took me a while to get used to digicams (I am selling my DSLR in the classifeds - shameless plug, not getting enough use out of it to keep it). Tropical - I have a FE2 body in good condition, if you are interested. Hard times, luxuries must go.

Camera has seen little use - digicam body only for S$499, with Soligor AF 28-105mm f2.8-3.6 $599. It is old model but in excellent condition and still give very good results. Excellent for serious photographers. You can get details about it in the link below. PM me if you are interested. Free delivery within Singapore, door to door if required. http://www.steves-digicams.com/s1.html

I have built another amp with the same schematic, using a dual -1.2 -0- +1.2V power supply. Using ordinary Sanyo 1000uF caps as output cap. And it works very well with my Grado SR60 now. Thanks to firefox for the suggestion to use the 1000uF caps. Hmm... I like the sound even if it is not as detailed as the Pimeta. The difference is probably not noticeable on MP3 playback. Anyone knows where I can get smaller 1uF polypropylene caps, smaller than the Rifa/Evox 1uF/250V caps that is. Thanks.

I have never used Blackgates before but is this as big a disaster as some has put it? No other choice of caps as good as Blackgates? Just wondering.

Wow, looks expensive, is expensive... I am OVER-wh|elmed|

tropical, I don't know but almost all the schematics for op-amps I have seen was for dual power supply. And I thought this design was great because it needed a single power supply only. Perhaps one of the DIYers who are EE trained can explain. Thanks.

Thanks bpribadi. It was your post asking about the power supply which got me thinking and checking Sijosae's site again. When I looked closely at his circuit board, I realised it was dual supply, with one additional wire going to the connector between the two battery. Anyway, I modified my amp for the dual supply last night and I must say it makes a difference to the sound. It is much more detailed. Even my Grado SR60 sound ok with it now. Really puzzling to me since I am not EE trained. Seems this is a good amp to make if just want a quick and easy amp for MP3 players. I am making another and will take pics of the progress. Maybe I will put it here as a guide for others to try.

Hi, I checked Sijosae's site again and found he actually uses a dual battery supply(1.2-0-1.2V) while I used a single power supply (2.4V-0). But my amp still work and sounds ok. Are there any advantageous in going for the dual supply? Gurus? Thanks.

Thanks digi01, I got the chip from Farnell in Singapore, costs about 90cents each!! The passives cost more.

Thanks Firefox, got the Solens from Wells Audio. Next time I get to Koba will look for the 1000uF caps. Wells sells them but the expensive variety.

Thanks bpribadi. You know me, I like sweets too much. The power is single +3V-0.

Thanks Firefox, wah, 1000uF must be quite a big cap. I can try increase the current output by stacking one more chip before it gets too high. BTW, where is best place for Solen caps? Thanks again. I was listening to this amp with a very old pair of Senns HD450 and it sounded pretty good for a portable amp. Source was an old Creative MP3 player. The advantage to me is its very low power consumption which means less battery charging. I gave up my portable Pimeta and converted it to run off a wall wart. It was drinking up 9v batteries, the re-chargeable 9v are worst as they are small in capacity.

Q00 - yes, it is stated in the discussion in HeadFi that it won't drive low impedence phones well. On my Grado, the details are just missing. Firefox - thanks for the tip, I will try it!

Hi guys, I made this amp using the 74HCU04 chip and the schematic from Sijosae's site. The power supply is just two AA batteries and a electrolytic cap. I stacked two 74HCU04 chips together for more current output. My built has a gain of 6. The sound is quite strange. Thru my Grado SR60, it is very dark, worse than the Burr-Brown OPA2134 in a CMOY. However thru my DT880, it sounds quite acceptable albeit still a little dark. It was mentioned in HeadFi that this chip is not suitable for Grados, so it must be true. I think this headamp is easier to built than a CMOY and it is much less power hungry. I am still using a pair of rechargeable AAs for almost 48 hours continuous running now and it's still going. Not bad.

Great looking amp as usual, good job, digi! Congrats.

Hey, a prosperous and peaceful year to both of you.

Wow, overwhelming!! DIY heaven. After all that work, how's the sound??!!

You are right on the first one, N@Z.

Hi stopme, welcome. I like the SR60 and you may not need any amp with it. It is quite efficient. But if I have a diy amp, I would connect it directly to the sound card. BTW - I am not a pro here.

Yup, I agree with nakedtoes. The Grado SR60 is value for money and seems much more solid than the PX100. The sound is excellent too.

Thanks huangyong!! Looking fwd to it. Now to collect the components.

Best wishes on this special day, TropicalRips. Wah so young.

The tube buffer sounds more like a "tube filter" to me, since it is actually used to change the sound rather than to buffer. Still it does look cute.

Hi borez, I just started using a SR60 just to see what Grado was about. Well, after running it in, I have to say it beats the PX200 substantially in terms of sound quality. I summarise what is my view: 1. Comfort - tie between both 2. Convenience - SR60 as it doesn't need to be folded/unfolded 3. Construction - SR60, the PX200 wire is especially flimsy and it is very microphonic, ie movement of the wire is transmitted to the headphones. 4. Portability - PX200, it is smaller and when folded and inserted into box, very neat. SR60 is not portable 5. Isolation - PX200 - some isolation from ambient sound but not as good as the in-ear designs eg Koss 6. Sound quality - SR60 by a long shot 7. Value for money - SR60 So that's my opinion. At the end, you have to decide and just take the plunge..... , if you really want good isolation, get the in-ear phones, I have sat thru a nurse screaming my name in a clinic with my Koss on. Only problems with the Koss was having to compress the foam each time I put them in, which happens a lot, since I can't hear when people speak to me. Regards.