My, those caps are big! ;-)
Looks good. Everything through-hole except op-amps?
It's hard to tell from the pictures, but I hope those big caps are spaced off the board a little as those wound caps can get punctured by the cut ends of the leads from the top-side components. Perhaps hold them slightly off the board with some hot-melt glue.
Looks good. Everything through-hole except op-amps?
It's hard to tell from the pictures, but I hope those big caps are spaced off the board a little as those wound caps can get punctured by the cut ends of the leads from the top-side components. Perhaps hold them slightly off the board with some hot-melt glue.
Thanks.
They are actually not as big as they look.
I did space them off the board about 1/8".
I would normally put some hot melt glue or double sided tape under them, but I new I would probably be changing components and I wanted to be able to do that easily on this prototype.
Everything is through hold except the SOIC opamps.
Cheers!
Russ
Hello Bins.
For now I am using these opamps. I Am quite happy with them and can't see any reason not to use them.
IC1 OPA1632(THS4131 would also work well here)
IC2 OPA1612(Lot of options here, but this opamp seems quite nice)
IC3 LT1113(have also tried OPA2227 with good result)
The gain is very much up to the builder.
I am quite happy with the gain as shown for MM and HO MC cartridges. Which is about 40db at 1Khz.
Cheers!
Russ
For now I am using these opamps. I Am quite happy with them and can't see any reason not to use them.
IC1 OPA1632(THS4131 would also work well here)
IC2 OPA1612(Lot of options here, but this opamp seems quite nice)
IC3 LT1113(have also tried OPA2227 with good result)
The gain is very much up to the builder.
I am quite happy with the gain as shown for MM and HO MC cartridges. Which is about 40db at 1Khz.
Cheers!
Russ
Hello Russ,
Thanks for the quick reply. I am really interested in trying this one. I am having the OPA1632 & OPA1612 in my inventory. I need to order the LT1113 chip.
Right now, I am using Nagra BPS phono stage. It is having a gain factor of 51dB with MM and 62dB with MC.
What should I change in the RETRO circuitry for attaining that gain level ?
Best regards,
Bins.
Thanks for the quick reply. I am really interested in trying this one. I am having the OPA1632 & OPA1612 in my inventory. I need to order the LT1113 chip.
Right now, I am using Nagra BPS phono stage. It is having a gain factor of 51dB with MM and 62dB with MC.
What should I change in the RETRO circuitry for attaining that gain level ?
Best regards,
Bins.
Shhhhh. My wife still thinks it's research and development.
As far as I am concerned the Hi Z circuit is finished. As soon as Brian Donegan gives the thumbs up we can offer kits to early adopters.
. Right now they would still be considered 'beta'. But still, I ordered enough boards that anyone who wants to experiment along with me is welcome to. Cheers!
Russ
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Interesting observation on vinyl nirvana
Digital...digital everywhere but when someone plays an LP all stops.
At a meeting of the Baltimore Audio Club earlier this year, at the home of a member that is lucky enough to have a very high end system we played many CD's comparing heavily modded CDP and comparing it to the Benchmark DAC
(I have yet to introduce the group to my Buff32). After a couple of hours of listening to CD's the host brought out a few LP's and with jaw dropping sound we were all in vinyl nirvana for the rest of the session. For the next few weeks I played LP's for my listening sessions. I did not start playing CD's until I built the Buff 32. I do as often I need to do, to get back to reality and play vinyl, usually after hearing some live music.
Just some thoughts
Digital...digital everywhere but when someone plays an LP all stops.
At a meeting of the Baltimore Audio Club earlier this year, at the home of a member that is lucky enough to have a very high end system we played many CD's comparing heavily modded CDP and comparing it to the Benchmark DAC
(I have yet to introduce the group to my Buff32). After a couple of hours of listening to CD's the host brought out a few LP's and with jaw dropping sound we were all in vinyl nirvana for the rest of the session. For the next few weeks I played LP's for my listening sessions. I did not start playing CD's until I built the Buff 32. I do as often I need to do, to get back to reality and play vinyl, usually after hearing some live music.
Just some thoughts
Mistake or...
Hi,
Got a nice paper from National on designing a phono preamplifier using LM47910 at: http://www.national.com/an/AN/AN-1651.pdf. In that application note, on page 3, it is stated that a 100pF capacitor is required at the input section for cartridge loading. But, in the schematic (Figure 3) given below, I can only see the 10pF capacitor. Is that a mistake or is that enough ?
Also, the resistor value stated in the statement is 47 ohms and the value shown on the schematic is 47K.
Best regards,
Bins.
Hi,
Got a nice paper from National on designing a phono preamplifier using LM47910 at: http://www.national.com/an/AN/AN-1651.pdf. In that application note, on page 3, it is stated that a 100pF capacitor is required at the input section for cartridge loading. But, in the schematic (Figure 3) given below, I can only see the 10pF capacitor. Is that a mistake or is that enough ?
Also, the resistor value stated in the statement is 47 ohms and the value shown on the schematic is 47K.
Best regards,
Bins.