Just some recent thoughts on preamps with GC.After having tried various pre's i.e.Pass BLS , op-amp buffered types etc I have come to the conclusion that they can sound initially better in every way particularly because of a perception of increased dynamics and bass.However...... recent auditioning again between them and passive types sugest that a certain harmonic purity is lost in the process.Ok you might need to turn the volume up a tiny bit extra for the dynamics but overall now I am back to listening with a passive device.I feel that if you tweak the gain up on the GC a little bit more the dynamics are better and of course the feedback is less which is a good thing and leeds to a more natural presentation.
king30 said:
I don't plan to make gerber files, and I don't even know how to make them.
I just plan to send the .brd file to www.olimex.com
They process .brd files and their price is good.
Does anyone have more comments on my PCB?
When just using one pair of electrolytics, do I have to use something like 200uF instead of the 100uF like planned when using two pairs?
Are the BUF634 and the OPA627 close enough now?
I'll guess I'll have to build it to get an answer to all questions
When just using one pair of electrolytics, do I have to use something like 200uF instead of the 100uF like planned when using two pairs?
Are the BUF634 and the OPA627 close enough now?
I'll guess I'll have to build it to get an answer to all questions
heatsink capacity
That would depand on your supply voltages. If you use +/- 15V the power dissipation of BUF would be just around 0,5 W.
With an ambient temperature of 20 Celsius and a 20k/W heatsink the BUF would heat up to about 30 degrees.
In my preamp the BUF are only lukewarm. So any heatsink will do.
Abo
Oops I just saw you use 18 V supplies. The power diss. of the device will increase up to around 0,55 W. That's all. Use any heatsink that fits and you'll be fine.
That would depand on your supply voltages. If you use +/- 15V the power dissipation of BUF would be just around 0,5 W.
With an ambient temperature of 20 Celsius and a 20k/W heatsink the BUF would heat up to about 30 degrees.
In my preamp the BUF are only lukewarm. So any heatsink will do.
Abo
Oops I just saw you use 18 V supplies. The power diss. of the device will increase up to around 0,55 W. That's all. Use any heatsink that fits and you'll be fine.
It does. Depending on load resistance.
But in normal operation as a preamp or cd buffer, the buf will stay in class A operation, and dissipation will not increase.
And it's better for sound too...
PS: I wouldn't go as high as 18 volts myself. For most opamps this approaches the absolute maximum rating which is never good. I've heard of opamps failing even below that value.
In my experience, increasing supply voltages over 15V will not improve sound.
But in normal operation as a preamp or cd buffer, the buf will stay in class A operation, and dissipation will not increase.
And it's better for sound too...
PS: I wouldn't go as high as 18 volts myself. For most opamps this approaches the absolute maximum rating which is never good. I've heard of opamps failing even below that value.
In my experience, increasing supply voltages over 15V will not improve sound.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.