You should look up op amp basics for a schematic. You could make an inverting or non-inverting amp. It's super easy and you'll learn a little something more than just getting a schematic handed to you.
You might draw it out by hand or on the computer and post it here for a double check. Really, it's simple.
Give me a ******* break! Your are no use to me at all. I simply wanted a box the does not apply RIAA equalization … that was the simple request. Instead I get a lecture on 78RPM equalizations, links to devices that cost thousands of dollars, I guy who throws out some parts values, and you saying "learn to design it yourself" GOOD, "asking for a schematic" BAD. I don't why I even bother with this forum. I thought forums were here to help people. I don't need to get pissed on because I asked for a schematic. I leaving this ******* forum for good so any further responses to this thread will not be read by me
We are all trying to guide you to a good circuit and pre-amp. No need to get hot about it.
There has been some very good advice and relevant questions posted here. We don't know your skill level or exact needs. Maybe cool down a bit, re-read the thread and think about it.
A phono pre-amp with no EQ is just an amp. 30dB gain is a good target, and the resistor values have already been stated.
How do you feel about building the power supply? That is a little more complex than the pre-amp circuit itself.
There has been some very good advice and relevant questions posted here. We don't know your skill level or exact needs. Maybe cool down a bit, re-read the thread and think about it.
A phono pre-amp with no EQ is just an amp. 30dB gain is a good target, and the resistor values have already been stated.
How do you feel about building the power supply? That is a little more complex than the pre-amp circuit itself.
Sounds like he doesn't want to DIY. What about a ADC with an instrument input, high impedance and 20 to 30db of gain.
https://www.long-mcquade.com/217263...nel-USB-Audio-Interface-wtih-Two-Mic-Pres.htm
$100 CND
https://www.long-mcquade.com/217263...nel-USB-Audio-Interface-wtih-Two-Mic-Pres.htm
$100 CND
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Do you mean the instrument input of a sound card? I've done that but the response is off because of the light load - often 500K -1Meg.
Maybe put a 47K resistor across the input, and perhaps a little cap? I have not tried that.
Maybe put a 47K resistor across the input, and perhaps a little cap? I have not tried that.
jsthomps, your response to the many helpful posts here was rude, inappropriate and rules breaking. Go reread the forum rules and decide if you can abide by them otherwise....
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I have one - you can just replace the RIAA network with a wire.
It uses 8 tubes though and requires 330V@60mA/12V@3A.
I have a large 78 collection, and RIAA sounds just fine to me... RIAA was developed as a kang of the warlier EQ's anyway.
Of course, all you really need to do is sample the record with RIAA, use a reverse RIAA filter in software, and then apply the filter you actually want.
Seriously, if all you want is a phono amp with no filter, JUST SHORT THE FILTER.
It uses 8 tubes though and requires 330V@60mA/12V@3A.
I have a large 78 collection, and RIAA sounds just fine to me... RIAA was developed as a kang of the warlier EQ's anyway.
Of course, all you really need to do is sample the record with RIAA, use a reverse RIAA filter in software, and then apply the filter you actually want.
Seriously, if all you want is a phono amp with no filter, JUST SHORT THE FILTER.
This will probably lead to another tirade from jsthomps, as it's not a literal answer to the original question, but another option would be to use an RIAA amplifier and apply both inverse RIAA and the proper 78 RPM correction in the MiniDSP. It could be the cheapest solution when you already have an RIAA amplifier and a MiniDSP.
How important is RIAA equalization if the application is listening, LPs which are all made post 1970s, you have tone controls, and the gain can be set with a trim pot.
Can I use a Headphone amp as a phono amp ? Have seen some really nice simple headphone amp designs.
How do I figure out the best loading resistor value if I know nothing about my cartridge other than its a MM.
Jsthomps check out the schematic on this link. It explains how loading is done and how to setup a basic opamp for phono.
http://www.hagtech.com/pdf/bugle3.pdf
You can also goto websites like easyeda or easypcb and they have thousands of free schematics and PCB designs you can use or mod.
Can I use a Headphone amp as a phono amp ? Have seen some really nice simple headphone amp designs.
How do I figure out the best loading resistor value if I know nothing about my cartridge other than its a MM.
Jsthomps check out the schematic on this link. It explains how loading is done and how to setup a basic opamp for phono.
http://www.hagtech.com/pdf/bugle3.pdf
You can also goto websites like easyeda or easypcb and they have thousands of free schematics and PCB designs you can use or mod.
It is critical.
No tone control yet made can perform disc replay equalization accurately to any of the dozens of curves apart from the flat one. 'LPs ... post 1970s' is irrelevant to a standard which dates from 1954, and to a thread which is about non-RIAA equalization for 78s. BTW the LP was introduced in the late 1940s
For the best archival solution, you want the Timestep T-03EQ A+ from Dave Cawley in the UK. It's a few grand but does everything to archival spec and is balanced.
I'm not aware of anything cheaper and balanced. Rek O Kut makes a cheap unbalanced flat preamp. It's fine for the price (see: https://www.audiosciencereview.com/...-o-kut-ultra-phono-preamplifier-review.34061/) What I usually recommend to mid-budget 78 collectors is the Parks Puffin, which has digital processing, meets most audiophile definitions, and has every 78 curve, including flat.
I'm not aware of anything cheaper and balanced. Rek O Kut makes a cheap unbalanced flat preamp. It's fine for the price (see: https://www.audiosciencereview.com/...-o-kut-ultra-phono-preamplifier-review.34061/) What I usually recommend to mid-budget 78 collectors is the Parks Puffin, which has digital processing, meets most audiophile definitions, and has every 78 curve, including flat.
Hi,
to #8 and #9, etc.
The first Monophonic of Mr. Fehlauer was inspired by the Scott amp, utilizing two knobs for lows eq and highs eq.
Number scales from 0-10 on both knobs allowed to comfortably dial in on almost any EQ curve with sufficient precision, following a two digits table.
Mr. Fehlauer presented a new improved Monophonic not long ago under his label audiospecials.
It can accommodate from MC to MM pickups and even the very high output enigmatic Pierre Clement cartridges.
jauu
Calvin
to #8 and #9, etc.
The first Monophonic of Mr. Fehlauer was inspired by the Scott amp, utilizing two knobs for lows eq and highs eq.
Number scales from 0-10 on both knobs allowed to comfortably dial in on almost any EQ curve with sufficient precision, following a two digits table.
Mr. Fehlauer presented a new improved Monophonic not long ago under his label audiospecials.
It can accommodate from MC to MM pickups and even the very high output enigmatic Pierre Clement cartridges.
jauu
Calvin
This direct drive Hitachi HT350 was picked up in 79. Its all thats left of the Original setup.
I remember growing up listening to this while it was paired to various Amps from Techniques to Akai. To Pioneer.
They all sounded amazing. So for now my plan is to just study the phono sections of these old amps and replicate one of them. If I can find the parts.
For the power supply I find a simple zener and 220-320 ohm resistor works.
Will share the schematic as soon as its finished.
I remember growing up listening to this while it was paired to various Amps from Techniques to Akai. To Pioneer.
They all sounded amazing. So for now my plan is to just study the phono sections of these old amps and replicate one of them. If I can find the parts.
For the power supply I find a simple zener and 220-320 ohm resistor works.
Will share the schematic as soon as its finished.
MC and MM balanced input flat preamps:
https://ka-electronics.com/shop/index.php?route=product/search&search=phono
The Danville dspNexus has a 47K differential input and optional capacitance loading. The RIAA is done in the DSP, so you certainly can access the output of the cartridge before EQ. This might be helpful if you are trying to add pop removal or want to explore alternate EQs.
I realize that this is very different than the previous posts.
Al (Danville Signal)
I realize that this is very different than the previous posts.
Al (Danville Signal)