ok so i am building a gainclone as poweramp and now i need a phono stage..
I've been reading around the forum, and moast pretty old threads.
dont really know if i want tube or opamp or watever..
just looking for somthing good and if possible simple.
for now i only need mm. who knows in the future 🤪
budget for parts 100-200ish
I've been reading around the forum, and moast pretty old threads.
dont really know if i want tube or opamp or watever..
just looking for somthing good and if possible simple.
for now i only need mm. who knows in the future 🤪
budget for parts 100-200ish
.......good and simple means to me building a phono stage
with an opamp........along a schematic from a good commercial
hifi amp, perhaps pioneer,yamaha or so what.
with an opamp........along a schematic from a good commercial
hifi amp, perhaps pioneer,yamaha or so what.
Figure 6 of "Noise and moving-magnet cartridges", Electronics World October 2003 maybe (page 42)? It's only meant for moving magnet. See https://worldradiohistory.com/UK/Wireless-World/00s/Electronics-World-2003-10-S-OCR.pdf If you don't care about the noise level in between records, you can get rid of the part around A2 and use a plain old 47 kohm resistor for input termination.
Like @mjf, I'd suggest a 1-opamp wonder, like this. Instead of using one dual opamp I might suggest two NE5534As, which remain hard to beat for phono MM. (NE5532(A) should be decent as well though, about on the level of the OPA2134 suggest at least.) You can always add a discrete MC prepre later.
Then you'll need some sort of bipolar power supply, preferably not too noisy - maybe LM317/337 based (with ADJ pin caps)? Some of these are readily available, you just have to add a transformer.
OP, what sort of experience level do you have? All of the above would require being able to come up with a suitable PC board layout and have it made, alternatively it would have to be wired up on perfboard or P2P.
Then you'll need some sort of bipolar power supply, preferably not too noisy - maybe LM317/337 based (with ADJ pin caps)? Some of these are readily available, you just have to add a transformer.
OP, what sort of experience level do you have? All of the above would require being able to come up with a suitable PC board layout and have it made, alternatively it would have to be wired up on perfboard or P2P.
i have no experience in making or designing boards .
p2p is no problem but it would be best if its possible to order pc board or get gerber files.
i have some basic understanding how electronic works.
p2p is no problem but it would be best if its possible to order pc board or get gerber files.
i have some basic understanding how electronic works.
If you read into MM/MC pre-amps in depth you will notice that the common theme is layout.
Just choosing a topology or even a schematic may prove disappointing.
Find a well proven design with a proven PCB layout.
The Pass Pearl 1 (MM) or Pearl 2 (MC) are both brilliant designs but may exceed your requirements.
John Linsley Hood has also published many designs with good proven PCB layouts.
It's easy enough to generate the required files for a published PCB design and then get the PCBs made.
Just choosing a topology or even a schematic may prove disappointing.
Find a well proven design with a proven PCB layout.
The Pass Pearl 1 (MM) or Pearl 2 (MC) are both brilliant designs but may exceed your requirements.
John Linsley Hood has also published many designs with good proven PCB layouts.
It's easy enough to generate the required files for a published PCB design and then get the PCBs made.
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It's not difficult to build an MM preamp that works well on a piece of perfboard, as long as you put the perfboard in a shielded box and put the mains transformer at a large distance from it. As soon as the mains transformer and the MM preamp have to share an enclosure, it will take some effort to get rid of hum.
I sort of disagree with that.
It doesn't take much effort as you say, if designed properly.
Because a while back I designed a MM preamp, along with a Sallen-Key filter for rumble, and an additional booster preamp, all in a 3x4x6 inch aluminum box - WITH the power transformer INSIDE, literally inches away from the PC boards.
And guess what?
NO hum!..... none!.....dead silence!
If "I" can do it, then it's possible to do.
So with that stated, all those 2-piece types of equipment like preamp/PS and such are more about Snake Oil than reality.
But I guess that the current "rage" about seperating power supplies and the products that are powered from them are designed to entice the public into believing such nonsense.
I never claimed it is impossible, just that it's more difficult than with the mains transformer at some distance from the amplifier.
Asides from working in a small enclosure, it wasn't that difficult for me.
It actually was fun.
Power transformers suitable for small preamps are quite tiny and any radiated magnetic fields they may produce are just as tiny.
It actually was fun.
Power transformers suitable for small preamps are quite tiny and any radiated magnetic fields they may produce are just as tiny.
That's not my experience. I built two moving-magnet amplifiers with the transformer in the same enclosure as the amplifier and in both cases it took some effort to get the hum level below the noise floor. I never had any issues with hum when using an AC wall wart. Maybe you used a better power transformer than I did.
In fact in one of the two cases, I resorted to using a separate enclosure for the transformer after all.
In fact in one of the two cases, I resorted to using a separate enclosure for the transformer after all.
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Have a look at „bugle 2“ from haglabs. Very nice, easy to build, good reviews... I built it and it _is_ easy to build it. Cost is below 100.–
Bugle2 - Phono Preamp PCB - Kit – Hagerman Audio Labs
https://www.diyaudio.com/forums/att...d1612944584-finding-phono-preamp-augurken-jpg
Well, there's your problem right there.
Using such crude items as soup cans is not a proper nor reliable way to built things.
I love my RJM VSPS and it checks all your boxes.
Good. Simple (very!). Easily in your budget ($40 USD for the kit).
RJM Audio- The Very Simple Phono Stage (VSPS)
RJM has other phono stages too. Worth having a look, IMO - RJM Audio
Good. Simple (very!). Easily in your budget ($40 USD for the kit).
RJM Audio- The Very Simple Phono Stage (VSPS)
RJM has other phono stages too. Worth having a look, IMO - RJM Audio