want to borrow: signal generator and oscilloscope

[loop_ 0]

anyone can lend me for 1 or 2 days?

 

i have zen headphone amp

 

http://www.headwize.com/projects/showfile....llerano_prj.htm

 

instruction on balance is:

 

Setting R17 (balance trimmer): You must use a signal generator and an AC voltmeter and/or an oscilloscope. To trim the Id(Q1)/Id(Q2) ratio, apply a test signal at the input – for example 1KHz - and measure the AC contribution across R10 and R12. Adjust R17 so that the contribution across each resistor is equal. You can try to vary this value while you're listening to the amp, and see for yourself the best setting.

 

recently i mistekenly tweaked the balance with only a voltmeter. obviously it didn't work and has turned out to be a big mistake. I'm very upset

 

anyone with the equipment to borrow? thanks in advance. pls PM me

 

hansel

[neutralzz 0]

go to any physics lab or related labs...inside should haf..

 

dont think many people have one at home

[loop_ 0]

know any lab which i can go to for free or with some payment?

[bpribadi 0]

For signal generator, you can use your PC or notebook, with freeware like Audacity

 

As for oscilloscope, last time I saw a lot of second hand ones in Kaichin (SLT 3rd floor, the shop that looks like a junkyard).

 

Not sure if there is any freeware that can make use of good sound card as oscilloscope. Maybe you can share to us if you find any freeware that can do the job well It' won't be realtime though (sound card latency sometime very bad ), but I guess maybe good enough for your purpose. As with the voltmeter, a good true rms voltmeter that can measure 1kHz, with fast sampling time might do the job as well

[jtfoo 0]

That's what I did for my zen. I used NCHT sound generator to generate a 1 khz sine wave. Burnt it into CDR and played it via my cdplayer. Most decent digital multimeter set at AC voltage is able to measure the voltage. I'm using the Sanwa CD8000.

[huangyong 0]

may be jtfoo can help??

[jtfoo 0]

This is the sound generator I use to create the 1khz wave file. http://www.nch.com.au/tonegen/index.html