Yea, you are right..packaging, just had another look.
yes it's the smd i am after, RS it is...free postage.
Give a guy i know the onkyo 7030c schematic and he has recommended some tweaks i.e larger value capacitors (same voltage) like the 2 that feeds op amps ..think they are going from 470uf x 16v to 6800 x 16v. he says ICs work better with their own power supply and by adding the larger value caps does the trick.
yes it's the smd i am after, RS it is...free postage.
Give a guy i know the onkyo 7030c schematic and he has recommended some tweaks i.e larger value capacitors (same voltage) like the 2 that feeds op amps ..think they are going from 470uf x 16v to 6800 x 16v. he says ICs work better with their own power supply and by adding the larger value caps does the trick.
I did a Teac UD H01 Dac with the larger caps , i had the caps already waiting for the dac to arrive, I give it a listen before the caps where changed and to be honest it was poor,I wouldn't have been happy with that in my set up , but i already knew this guy was singing it's praises with the larger caps added so the next day i was adding the caps ( the caps on the dac were smds so the new ones were added over the top of the smds legs and boy did that dac sing that night.
still using the dac, but i thought i would upgrade the onkyo to compare..though dac will be hard to beat
still using the dac, but i thought i would upgrade the onkyo to compare..though dac will be hard to beat
Last edited:
Bypass caps simply lower the AC impedance between their two terminals. This might change how signal currents flow among the power supplies and ground, or it might not. For example, if the bypass cap has a lower impedance than the power supply, then current drawn near the bypass cap will be sourced more through the bypass cap than the power supply - i.e. more from the other side of the cap than the power supply.
Is that good? Well, if it's a bipolar powered amplifier, that current will be a half wave rectified copy of the amplifier's requested current, and the other terminal of the bypass cap will be ground. So, in essence, you've just injected a lot more rectified signal current into ground at the point where the bypass cap is connected to ground. Is that good? Depends on the layout. Also depends if you have the other half of the rectified supply current available to sum together to effectively 'un-rectify' it.
What if the power supply has a really low AC impedance, lower than the impedance of the new, larger cap. Will the new larger cap do anything except make you happy that you've "improved" the circuit? No.
Yes, a long winded rant, but I hope you get the idea that simply increasing bypass cap values can do a lot of things to how a circuit and its PCB layout works, and not all of them are good, and some are downright ineffective. Large power supply bypasses can be used effectively, but considering that they simply couple more signal current into ground, your ground system must be very low impedance for that to be something good to do. If the PCB lays out ground like some late 70s design, using a narrow, winding trace that takes a long path through the circuit, that extra signal current in ground might be a mess, as it will be coupled into a lot of components that are already only loosely coupled through this poor ground.
Oh - a single supply discrete circuit? Then no worries about rectified PSU current - there is none, and larger caps will help add to the usually non-existent power supply rejection.
Again, it all "depends", and unless you look at the circuit design, PSU design, the physical layout of the PCB, and where you are going to physically attach these new bypasses, nothing meaningful can be said.
Is that good? Well, if it's a bipolar powered amplifier, that current will be a half wave rectified copy of the amplifier's requested current, and the other terminal of the bypass cap will be ground. So, in essence, you've just injected a lot more rectified signal current into ground at the point where the bypass cap is connected to ground. Is that good? Depends on the layout. Also depends if you have the other half of the rectified supply current available to sum together to effectively 'un-rectify' it.
What if the power supply has a really low AC impedance, lower than the impedance of the new, larger cap. Will the new larger cap do anything except make you happy that you've "improved" the circuit? No.
Yes, a long winded rant, but I hope you get the idea that simply increasing bypass cap values can do a lot of things to how a circuit and its PCB layout works, and not all of them are good, and some are downright ineffective. Large power supply bypasses can be used effectively, but considering that they simply couple more signal current into ground, your ground system must be very low impedance for that to be something good to do. If the PCB lays out ground like some late 70s design, using a narrow, winding trace that takes a long path through the circuit, that extra signal current in ground might be a mess, as it will be coupled into a lot of components that are already only loosely coupled through this poor ground.
Oh - a single supply discrete circuit? Then no worries about rectified PSU current - there is none, and larger caps will help add to the usually non-existent power supply rejection.
Again, it all "depends", and unless you look at the circuit design, PSU design, the physical layout of the PCB, and where you are going to physically attach these new bypasses, nothing meaningful can be said.
Did the tweaks to the onkyo c-7030, I listen to the cd player before i did anything and to be honest i was never going to be happy with it in my set up, i replace the caps first, there were 5 in total , 2 for the DAC, 1 for the REF of the dac and 2 were for the op amps.
I give it another listen, i could tell things were working better but still wouldn't have been happy, so next came the op-amps and boy what a difference to the sound, vocals are the best i have heard in my set up, bass is deeper and tighter, infact the onkyo is staying, hearing things i never picked out before.
I give it another listen, i could tell things were working better but still wouldn't have been happy, so next came the op-amps and boy what a difference to the sound, vocals are the best i have heard in my set up, bass is deeper and tighter, infact the onkyo is staying, hearing things i never picked out before.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.