Which DIY phono-stage gives great results?

[Fasterdamnit]

But it will be absolute fidelity with battery power-supply I would ad 100uF capacitors for fast current peaks.

From V+ to ground for a current reserve?

I used this op amp in both my modded AT PEQ3 (24VDC and good caps) and Hagerman Bugle. It came in second to the LME49990 and a 49990/opa2134 combo. So I decided to try a KISS phono pre with one. Thanks for all the help!

 

[Helmuth]

From V+ to ground for a current reserve?

Yes with a switch when the amp is of also the the cap must be detached from the battery.

 

[Fasterdamnit]

Yes with a switch when the amp is of also the the cap must be detached from the battery.

Excellent!

 

[Fasterdamnit]

It's Alive!

Thanks to DIYaudio in general and Helmuth in particular! I built the phono pre per the National Semiconductor LME49720 datasheet. It sounds very nice on it's first album! It is clear and detailed. Better than the modded AT PEQ3.

Two op amps with left and right running thru each chip. Panasonic polyprop caps when I could find them in the right value. Simple is a good thing! Two more 9v batteries and I can run it +18v/-18v.

Schematic and poor phone pic of the running, bare Rat Shack board.

 

[Helmuth]

Thanks to DIYaudio in general and Helmuth in particular! I built the phono pre per the National Semiconductor LME49720 datasheet. It sounds very nice on it's first album! It is clear and detailed. Better than the modded AT PEQ3.

Two op amps with left and right running thru each chip. Panasonic polyprop caps when I could find them in the right value. Simple is a good thing! Two more 9v batteries and I can run it +18v/-18v.

Schematic and poor phone pic of the running, bare Rat Shack board.

Have fun.😎

 

[FdW]

Thanks to DIYaudio in general and Helmuth in particular! I built the phono pre per the National Semiconductor LME49720 datasheet. It sounds very nice on it's first album! It is clear and detailed. Better than the modded AT PEQ3.

Two op amps with left and right running thru each chip. Panasonic polyprop caps when I could find them in the right value. Simple is a good thing! Two more 9v batteries and I can run it +18v/-18v.

Schematic and poor phone pic of the running, bare Rat Shack board.

That’s exactly what I did. First build the lme49710 application note version, and it sounded real good (even with the ne5534’s that I used). Next thing I did was try to improve it, made it balanced in, and added a hefty power supply. It sound truly wonderful, the big eared friends are very happy 🙂

http://www.diyaudio.com/forums/analogue-source/165603-balanced-input-all-dc-coupled-riaa-preamp.html

Happy listening,
Regards,
Frans.

 

[Helmuth]

Hi Frans,

You really made a lot of work of your phono stage. Did it work to make it humm free with the transformer in the same enclosure.

And very nice finish on the front of your enclosure. What is that CNC.

 

[FdW]

Hi Frans,

You really made a lot of work of your phono stage. Did it work to make it humm free with the transformer in the same enclosure.

And very nice finish on the front of your enclosure. What is that CNC.

Helmut,

For as far as I can measure and hear it is absolutely free of hum(m) or any other power supply related noise. The power supplies are in u-metal encasings, the other electronics is in copper cases (2mm thick). I have build 2 pre amplifiers, one for my MM (a Shure V15xMR) and one for MC (in use by a friend of me). We are both very happy with the result. The front plate has been machined, cnc, by Hi-Fi 2000 contenitori per l'elettronica, case modding HTPC, Galaxy, rack, DIYaudio, computer cases, front panel express, knobs,milled Handles, milled fronts, hi-end, in Italy.

Regards,
Frans.

P.s. all boxes inside the frame are fully isolated from each other (except for one common ground connection).

 

[Helmuth]

KS is polystyrene, interleaved film and foil, 1%, radial lead box type, low inductance, non-aluminum, other BS.
If you like, i'll throw in 4 KS 3280pF as well (i have multi-K in every value, but no 3n3).
Sponsored by the Phono Liberation Front (PLF), includes a freebie envelope and stamp.

That was English, i think.

Hi Jacco,

I just opened the postbox and found the capacitors you send me. Guess what direct got the welder and put them on the circuit board they are about 15 times the size of the MKT but it wasn't that difficult to place them.

I hear a more refined high frequency and smoother sound definitely the best I had in the preamp. It appears to me even the soundstage improved in width.

Jacco thanks for helping this poor vinyl-lover to improve his preamp.

 

[jacco vermeulen]

My pleasure.

 

[Helmuth]

For people how like to simulate the amplifier here a zip with the data for simetrix. Simetrix is freeware version (and also professional comercial available).

 

[Helmuth]

Now I added a DC servo to it Like in the design of Frans. I am just pimping the design a bit.

 

[PA0SU]

For this subject (MD) I always use an LT1028, but I'm afraid that op amps are forbidden on this thread?

 

[wjam]

phono amp

I built a 2 stage 6c45pi with passive RIAA between stages.

Sowter 8055 input Tx and a SAC TVC on the way out (kind of passive line stage - but more importantly drives my JR model 1 balanced)

I run each 6C45 with a VR tube I use CCS on the anodes and also a bigger CCS into the VR tubes. So each tube has it's own super duper regulated supply. This was very worth it.

It's super quiet. No hum no hiss and very many miles better than the Audio Research pre-amp it replaced. I hear tape hiss frequently on the vinyl and then when the gain is lowered on the recording I hear much less noise from the vinyl/TT/ pre-amp than the actual recording. I'd say in 70% of cases. Therefore I think I'm going in the right directio, However.. this wasn't a cheap DIY phono amp.

 

[Bksabath]

For this subject (MD) I always use an LT1028, but I'm afraid that op amps are forbidden on this thread?

Sorry then for posting this I am not good enoug to design discrete component so far but I am learning..

I had a split passive MC (60dB) balanced in that I have cooked myself following reading up the great Douglas and following advice from Joachim Gerhard, (most Nice and helpfull Human)

It was nothing special (I have no pretence to be a designer) but worked / sounded better than what I had from the shop.

After 3 years of trouble free operation (Is powered by rechargeable batteries)
I think it may be worth a litle for somebody that like to cook it's own.

Then decided to see if I could improve things a bit
So there you have it.

LT1028 balanced in, single shoot passive RIAA MC Phono pre.

I am going to make final PCB this morning in the mean time get a peck

On the bread board a THAT 1646 to make the output from inverse RIAA balanced and the DC servo DC is at less than 1 mV at output.

I supose you could have a good look at my Knobs on the scope top is the imput to the passive RIAA botom is the output DC coupled from the pre.
Yess 5 volts division on a 12 Volts rails suply

IMO less than Ideal set up with all those vires and on the open so I should expect better once in the box.

Really all I would like to say is get building...