heady

aaa, your PPA is on Tangent's board? Would love to listen to it. Hmmm....

bpribadi, there is this guy on headfi who posts a lot and seems to be expert, he said above 2-3 buffer chips, the improvement is marginal. I really don't know but we will know if you built your amp, as we can test adding one buffer at a time and listening.

I am trying to save space on my PPA board but to put in Glassman's buffer, I need the space from 9 holes square in the perfboard. So I will end up with the ability to test up to 4 buffers as well. But I don't think I will finish mine before you. I am still tinkering with my pimeta, decided it is too good to put into a tin with only one cap. I am working on adding the full complement of caps and putting it into a bigger casing. Good thing I went modular, no problem in changing.

Let's have a session end of the month to listen to our pimetas. Also need to collect the adaptors from you.

Regards.

Bpribadi, don't forget, not need to wait for shipping. I am interested in the plain old copper stuff. Silver's too rich for me Let's see when we can go...

Techaddict, if it is any consolation, the person cannot get chips free all the time. Samples sent out are limited in quantity and frequency. The chip company not stupid lah. But this person should not have sold the chips, it is in the agreement to get the samples. Like Bram said, don't let this spoil your day and outlook on this hobby.

AhFartAudio quoted for the silver and copper wire respectively:

>>We have the silver OCC 24 AWG for $16/m. Copper OCC 20AWG $2.4/m

I've just remember that this place sells silver wire but have never bought anything from them, as the shop is only by appointment. Don't try to visit the place on weekdays, seems the audio guy is there only on weekends. I've seen some uncle at the place selling odds and ends on weekdays. It's near Koba, in the HDB block beside OG.

http://www.ahfartaudio.com/

domi33,

http://www.sgheadphones.net/index.php?showtopic=2571

Bram, 5 buffers!!! I am thinking of buying Glassman's buffer which is diy and cost US$40 for a set of 3 with parts included. Only problem is smd parts! I read on the headfi sites that it is just below the LaRococo buffers in sound quality. I will put up the layout for my PPA clone once I finalise it.

BTW - I ordered the OPA from TI last Friday night and got them today!! That's fast!

Wow, you all are really dedicated diyers. Somehow I don't get very excited over cables. I must be Maybe I'll change my mind after I auditioned whatever bpribadi builts with his silver cable.

Bpribadi, US$17.50 shipping, 1-2 weeks, from HomeGrownAudio.

Bram, that is one sweet looking amp you built for your brother. Never tire of looking at it.

aaa, a US$1 per foot and buy a few hundred feet? Wow, that's a few hundred S$... I will go OTOH, I don't mind buying some good copper cable as Bram said.

aaa, the young man at Koba told me it is silver and I did not enquire more. I just looked at the small sample I cut and you are probably right. On one side, I could just about see some copper coloured strands right in the middle, need a magnifying glass to see. The other end was all silver coloured, probably due to the way it was cut. This cable is quite thick and stiff and has teflon insulator. Probably used by the tube builders.

But I also wonder if buy expensive silver cable, then must use silver solder or else you still get tin/lead in the transmission line right? I feel if I can use good quality copper cable then it should be good enough compromise. I am not a keen fan of cables, even for my normal hifi, sorry.

Bram, where did you get the bare copper wire for the Black Amp?

Thanks.

Anyone has opinion as to whether the Alps Blue is better than those ALPS pots we bought from Farnell?

I know that Koba in People's Park Centre sells them and I've heard that LHS in SLT also sells silver wire. But I don't know the quality or gauge since I have not used them. Are you intending to use silver solder as well?

Good stuff Bram. Lot's of hardwork there.

Bram, Makes sense to me.

Hi bzy83, what do you propose the group to do? We already have a group here, the people who frequent this forum. If the others are like me, I do most of my building and planning late at night when family is sleeping, we won't be able to actually meet much.

I am planning a clone of a PPA but without the elaborate power isolation transistors which actually makes it closer to a Pimeta than a PPA.

Bram, do you understand it? Not really sure except that it reduces cross talk.

Thanks Bram.

Hi Bram,

Question for you. If the battery supply drop below the regulator setting, what happens? Eg, you set the regulator for +7V and -7V supplied by 15V input. When supply voltage is more than 15V, the regulator will reduce the voltage producing heat. But what happens when the supply voltage drops below 15V. Is the output voltage maintained till a certain point?

Thanks.

Thanks Mackie for the explanation, I am relieved to know I am still a good boy Are there girls here??

Just a report of a change of the Nichicon cap to an Elna cap of same capacity. I changed the Nichicon 1000uF 35V cap (sorry not FineGold, thought it was) to an Elna 1000uF 25V (not a Silmic) yesterday and left it running over night and didn't like the sound from the beginning. Till now it still sound dark although bass has improved. I expected the bass to change but not the higher frequencies. ??? Anyway, I changed back to the Nichicon, I like its sound better.

Bram, you are right about the joining of the L/R channel at the socket. Now I remember the explanation from the site but you know, I am not electronic trained so I don't really understand it. I just follow the schematics and let the people who know do the thinking. When I did this Pimeta clone, I wondered if I did anything wrong but turned out my interpretation of the schematic was ok and the built worked. Phew!

Bram, in CMOY, virtual ground and signal ground are the same. In Pimeta and PPA, the output ground is supposed to be isolated from virtual ground so as to isolate the (theoretical?) effects of the L/R opamp on it. The input ground has a connection with the virtual ground but it is input into R1 and then fed into the Signal Ground opamp, the output of which goes to the output signal ground.

In the PPA, the isolation is further carried to the power supplies and virtual ground of all the channels, with each channel having their own virtual grounds and TLE. Which is the difference between the Pimeta and PPA.

That's what I think the schematics in Tangent's site meant.

Paul.

Can anyone enlighten me what i did to get this 0% warning bar in my posts? I'll try to be good after that. Promise.