Show me your fave phonostage circuits.

[Poindexter]

I just scored a turntable.  Pretty nice Pioneer belt-drive, I had one in the hippie daze; lapped the platter and arm bearings, balanced everything out, and it was the envy of stoned Honolulu with a high-end Shure for the tooth.

Gonna do it again, but I need a killer phonostage.  Not nice; not BFB, not anything else; S O A!

Thankew,

Poinz

[SY]

Cartridge?

[andyjevans]

I need to build a phono stage as well so will be following this keenly. One of my ideas was to start with an LT1028 op amp to get the initial gain quietly, then hand over to an ECC40. I could then finish off with a DHT stage in push pull into an OPT like LL1540.

I'd like a DHT in there, and I certainly like the ECC40 better than the usual 9 pin suspects, plus I've always liked the sound of diff. pairs with CCS under into an OPT - no caps.

Don't know in this case whether to put the passive RIAA equalisation before or after the ECC40

How does that sound?

Andy

[analog_sa]

Originally posted by andyjevans

How does that sound?

Like an opamp riaa.

[andyjevans]

`How does that sound?

Like an opamp riaa.


Hmmm.... some biting cynicisms here! I use the LT1028 in my current phono stage. It's quiet and sounds pretty good to me. Are opamps completely beyond the pale?

[kevinkr]

Originally posted by andyjevans
`How does that sound?

Like an opamp riaa.


<snip>

Are opamps completely beyond the pale?

For many of us here, yes. I do use them in digital electronics to a limited extent but prefer the THS4131 in all digital applications. (OT: My digital stuff is all balanced internally and I use transformers to go from balanced to unbalanced output.) Tubes absolutely everywhere else..

I can highly recommend the D3A (triode connected) or 5842, depending on required gain. Both in carefully designed circuits are capable of significantly better than 2nVrtHz with 1kHz noise bandwidth in a properly designed and implemented circuit. Quiet in the same sense that your op-amp is quiet and no sand in the signal path.

[dtut]

Poinz,

For all kinds of reasons this may provoke the Purity Police, but, if you know someone with a Scott integrated/receiver, check out the phono pre. Charles Hansen has an updated version of it in the July '06 AX. I don't remember if Hansen mentions it, but lifted dc on the heaters helps.

[andyjevans]

I can highly recommend the D3A (triode connected) or 5842, depending on required gain. Both in carefully designed circuits are capable of significantly better than 2nVrtHz with 1kHz noise bandwidth in a properly designed and implemented circuit. Quiet in the same sense that your op-amp is quiet and no sand in the signal path.>>>

Kevin (or anyone else) - can you point me in the direction of some schematics with the 5842/D3A? I have both in my collection.

Andy

[tubelab.com]

Hmmm.... some biting cynicisms here! I use the LT1028 in my current phono stage. It's quiet and sounds pretty good to me. Are opamps completely beyond the pale? ........ For many of us here, yes. ........ if you know someone with a Scott integrated/receiver, check out the phono pre.

OK, I'm gonna get it for this one. I had been using the phono stage in a Scott "Laboratory Reference Amplifier" (I don't remember the number and I am 1200 miles away) while working on something better. Something in the power amp section (not currently used) started smoking, so I gathered up some sand and built a chip phono stage. It uses a National LME49720. The circuit is on the first page of the data sheet. It works quite well, and is mounted inside the turntable so there is no hum and noise pickup. I have been experimenting with tube phono stages, but haven't bettered the sand preamp yet.

Another member sent me the circuit for his "top secret phono pre". It uses the D3A which is scarce in the US. I have finally gathered all of the parts (like a year ago), but haven't had the time to build it. It will be the next one to challenge the sand!

[ErikdeBest]

Hi Andyjevans

In valve amplifiers, third edition, Morgan Jones shows a schematic with the EC8010 (which is similar to the 5842). You could start from there...additionaly, the book brings enough information to make any wanted adaptation to the circuit.

Erik