Phono preamp kit build and test - Elliott Sound Products

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Күн бұрын

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@MarkErikEE 6 ай бұрын

Rod is the legend. Huge amount of valuable info on his website. I'm glad that your build worked out so well. I've collected all the parts for it, but it is languishing under other half-finished projects - some of them Rod's as well. Listening to vinyl is similar to listening to CD when it's raining, but vinyl has the ambiance built in.

@gamerpaddy 6 ай бұрын

rod elliot's projects are nice. no bs. i built this preamp aswell a few years ago and put it side by side with some other hifi equipment and it sounded the best out of them. also built the dc blocker for mains as my transformers started to hum at certain times a day. once you buy one of his pcbs you get access to the backend website with more stuff and schematics

@peterlarkin762 6 ай бұрын

Oh this is good! I have built loads of audio circuits over the years - Rod's are the ONLY ones that I still use daily (P101 amp, P97 Preamp with tone, P87 Balanced to unbalanced converter, P06 phono pre etc.) Rod Elliott's site is probably the best audio electronics resource you can get, the amount of education and tested circuits the guy gives away is amazing. And if you buy a PCB, you get more updated schematics and build guides. I've been using the P06 for a over a year and added a rumble filter (P99) to it last month - it was good before but the rumble filter is the cherry on top. I didn't mind a bit of subsonic speaker excursion but the filter tightens up the bass considerably and seems to clean up the mids as a result.

@MichaelBeeny 6 ай бұрын

Note this preamp is only suitable for magnetic cartridges of about 3mV output. Cheaper ceramic or crystal cartridges will not be suitable for this preamp. Mostly due to the RIAA correction and high sensitivity. If you have a crystal or ceramic cartridge you do NOT need RIAA EQ. What you will need is a high impedance input of around 1-2 meg ohms. A preamp with a fet input would probably provide this but you could simply put a series 1 meg resistor. Most ceramic cartridges output anything from 100mV up to and over 1 volt and may not even need a preamp at all. The cheaper and nastiest ceramic cartridges, ironically, give the most output.

@supercompooper 6 ай бұрын

Can you explain why if you have crystal or ceramic cartridge you would not need RIAA EQ? I thought that the grooves in the vinyl themselves were written with the RIAA equalization and you always need to undo it when you read back from the record?

@SuburbanDon 6 ай бұрын

Good question.

@MichaelBeeny 6 ай бұрын

@@supercompooper It's simply because, if you feed the crystal cartridge into a high impedance 1-2 meg ohm it's a characteristic of the cartridge that it will reverse the RIAA curve without further circuitry. Hence old type valve record players did not need RIAA correction as the input impedance was already high. A mag cartridge needs a 47k impedance. I hope that makes sense.

@Mikexception 2 ай бұрын

@@MichaelBeeny It is fair explanation, anyway it may be explained also in other way. RIAA curve was implemented aiming to increase the time of vinyl recording from standard to Long Play . It was designed so that all harmonics would cover the same horizontal sspace on disc which is not natural. in nature low harmonics have much bigger amplitude than higher. It was the issue leading to need of big "standard" surface in older records. . When reading LP all harmonics force the needle to deviate in the same secured by RIAA ampitude which is actualy emulating opposite nature "curve" . When we use cristall pickup it also on LP vibrates with created amplidude the same for all harmonics . Cristall pickup when no loaded creates the same static volatge for equal ampitudes - it results in flat output characteristic. With use of low input impedance like 47 kOhm resistance we can change cristall operation so that it wlii behave like magnetic - discharge will be so fast that time of voltage support will be significant, That is how some RIAA corrected preamps have separate input for cristall pickups too. . With magnetic pickup voltage is induced according to speed of needle vibtration not amplitude. That speed by applying RIAA has slowed and proportionaly voltage became affected . This is why we correct it up in pramp.

@Elecifun 6 ай бұрын

Even on perf board the Rod Elliott circuits work great. I built ESP project 3A 60 -100 watt amp on perf board and it sounds great. Great history recap on vinyl recordings and reproduction 👍

@peterzafian5601 6 ай бұрын

Thanks for this John. My build of this ESP board sounds really nice as well. Im currently trying which PS unit sounds best with it.

@antibrevity 6 ай бұрын

That Elliot collection is nice.

@Stelios.Posantzis 6 ай бұрын

Would you be able to share the name of the book you are referring to in the video? Could you also please share what the overall cost was? Granted, this will not include the power supply cost as it wasn't populated (perhaps you have a quote for the power supply parts kit) but it is an indicator. For me, I guess the standard to compare against for op-amp based RIAA preamplifiers would have to be the Lounge Audio preamp which is probably very hard to beat, at least within the USA, for around three hundred bucks for their base version. The benefit with ESP kits however is that you can customize the parts and tinker around to your hearts content as well as have the flexibility on the choice of the power supply.

@JohnAudioTech 6 ай бұрын

"HI-FI manual" by Fawcett Publications, 1954. Perhaps the person who sent me the preamp kit could chime in on the cost.

@Stelios.Posantzis 6 ай бұрын

Thank you for the reply@@JohnAudioTech. I managed to figure it out - by Donald Carl Haefler. Interesting little read. In the past I used to eschew antiquated publications by dismissing them out of hand as outdated. Now I find I indulge more and more on the hidden treasures one can find inside them. We often take a lot for granted without knowing neither the history nor the theory behind choices presented to us (or perhaps treated by us) as undeniable facts. If you ever build a power supply for the preamp, it would be interesting to know your impressions on the performance of the battery powered version vs. the ac mains power supply version.

@olliehemstock2234 6 ай бұрын

Thanks John for posting this and showing the pre-amps true performance… inspiring me to get back to troubleshooting my own build!

@gkdresden 4 ай бұрын

The opamp selection LM4562 is very good. It has a really low input referred noise of only 2.7 nV/sqrt(Hz), low distortion and good linearity. In my last phono preamp projects I have used the NJM2122 which has an even lower input referred noise of 1.5 nV/sqrt/(Hz), which is almost 6 dB less noise for just 1,60 € per device at Mouser. The LM4562 costs 2,65 €.

@olliehemstock2234 6 ай бұрын

I also have one of these, built using LM452s and high quality passives, all matched, powered by Rod Elliot’s recommended dual power supply board and a toroidal transformer, both in a separate case. I must have messed up the implementation so how as it plays but I cannot seem to stop it humming/buzzing

@JBBrown-hh4rc 10 күн бұрын

If you are going to use batteries for your power source, consider using rechargeable 18650 batteries. I've used them on the Accuphase C-3850 clone preamp and it's a great option. BTW, I built your preamp that you use in testing amplifiers after designing a pcb for the circuit. Thanks!

@johnsampson1096 6 ай бұрын

Good presentation, John! If you get a chance, try to obtain a schematic for a Fisher 50 C3 preamp. It was quite a unit mono preamp. I had one and lost it on an unexpected move. It would make great content for a feature video.

@U2WB 4 ай бұрын

Great video. Are there any kits for building a preamp for a moving coil cartridge ?

@Choralone422 6 ай бұрын

Thank you for the explanation of vinyl EQ with regards to the phono preamp! Back in the early 90s I had a friend who into collecting various punk music releases on vinyl. I always wondered why some of them sounded really tinny and others didn't. I'm guessing either whatever he had for a preamp wasn't doing the proper EQ or the some of the releases had some funky EQ settings, possibly due to the amount of just plain noise on the records.

@peterlarkin762 6 ай бұрын

Some records just sound awful, it's often how they are mastered to vinyl and how good the pressing is. I got a new Dire Straits record where there is bad sibilance on some tracks regardless of stylus, tracking weight, preamp.

@Mikexception 2 ай бұрын

More than people expect depends on specific of home system sounding on one side and reproduced sounds and recording engineering on other - system reproducing with overlaying resonances in audio band may sometime be sensitive when music contain them more then others. like often opera vocals resonating with middle low, choirs also recordings with lot of reverberations and low sounding instruments. Or much less when recording does not contain "sensitive" harmonics. . It is more observed in analog recordings where band of frequencies is often naturaly narrow (which do not make them unpleasant, it is just opposite on good home system) because of natural instruments and not available for analog studio strong mastering to avoid noise increase It is not observed in digital where by mastering lot of details may be emphasized to cover standard deficiences of home sytems . In my collection from 60 - 70ties I have no any not equaly interestingly recorded LPs, Even I had major problems to listen to some of them but rectified all with speaker/amplifier tuning, achieved it few times and that gives me right to say so . My observation is also that many people complain about all records from 60 ties - they say it is crap. Up to my knowledge this is because in these times music was 50% created with electric guitars often distorted, sharp vocals and percussion . These sounds are very poorly reproduced by modern systems and speakers, leaving listener with some puzzling not nice impression . . In those times guitas and sharp vocals were most important and low bass ans high sopranos were not even much desired so recording engineers put no much attention on them Now whole attention goes to over emphasized low bass and top sopranos. which were not caried then . But with right reproduction they still amaze and surprise .

@jakep8484 6 ай бұрын

Nice, I remember when your video where you breadboarded this phono preamp came out, I almost built this at that time but built a different one and wrote off op amps at least for phono because I felt they sounded dull and dry and a little harsh on the top end. I just recently designed and built a mm phono preamp on a breadboard and it is dead quiet without shielding. It's all discrete transistors so it's less picky, Def got me back into vinyl though sounds great.

@polkiju7 6 ай бұрын

Been monkeying around with a Ruscco TT and five or so Phono preamps some from the early 1960’s (Broadcast Types). Same bird’s nest wiring as you have. I felt some relief (schadenfreude actually) at your oopsey moment with the PSU. Turntables and their attendant parts are incredibly unforgiving!!! Thanks for the great Vid.

@pda49184 4 ай бұрын

Great stuff John, as always.. I can't think why, but as I was watching your presentation my minds eye could see and hear Snickers up on the bench..

@JohnAudioTech 4 ай бұрын

Hard to believe he's been gone for 3 years now.

@m3chanist 6 ай бұрын

Great John, cheers. Got a buddy who will enjoy this vid, as did I. And thanks to your mystery benefactor, a fine gift indeed, nice job.

@cougar1861 2 ай бұрын

Elliott has a power supply PCG for this pre-amp: P05 Revision D (It's samller than the pre-amp PCB) Thanks for thr video. Waiting for the final configuration.

@carlfranz6805 6 ай бұрын

Nice to know ESP still exists and it is still worth the trouble. I have about 10 boards of his.

@stonehead45 Ай бұрын

Can I connect the output of this directly to the aux input of my system or a preamp is needed? I expect the output is 300-400mV which is consumer line level. I have a sound bar that has a aux in (Harman Kardon Citation MultiBeam 700). Rod is saying we can increase R6 from 100k to say 220k (max before it starts clipping) to get more gain. I wonder if that is needed in my case.

@JohnAudioTech Ай бұрын

Yes, you can connect this to the aux input. The preamp is plenty hot. I don't think you'd want more gain.

@stonehead45 Ай бұрын

@@JohnAudioTech Thanks a lot John :)

@andymouse 6 ай бұрын

Nice one John !...cheers.

@QoraxAudio Ай бұрын

11:54 That hiss is probably thermal noise - inevitable and inherent to the nature of electrons inside any conductive material.

@HazeAnderson 6 ай бұрын

I just had a thought --- how cool would it be to build a mic level only circuit for education? (To show how limiting they are and the problems to be solved ahead.) I think we take the whole concept of preamps for granted, that is ... we have forgotten the days before we knew to build and use them. When was the jump from mic level to line level anyway? 1950s? Thanks for another video! 👍

@victoramicci840 6 ай бұрын

Cool, nothing like the inconvenience of vinyl!

@keithblume5159 6 ай бұрын

My current Denon 103r cartridge is only .25mv. I repurposed a pair of Microphone input xformers from an old microphone mixer to step up the voltage

@gkdresden 4 ай бұрын

It is important to notice that you handle signal RMS levels of 5 mV for MC or 50 mV for MM cardridges (the ESP design is for MM cardridges only, if you want to use MC cardridges with it you have to use at least a 1 : 10 input transformer). A grounded metallic enclosure is absolutely a must. I also think that the PCB is not conveniently designed for phono purposes. You need to have a ground plane, especially for MC cardridges. Furthermore you have to avoid larger distances of the peripheral devices from the opamp and make sure to avoid larger conductive loops at the inputs and you have to use rf filtering at the inputs as well. The ESP design has also several functional disadvantages. The distribution of the RIAA filter is not convenient. Especially the second opamp has no active filter function. The high-frequency roll-off is done by a passive 1st order filter after the second opamp output. So there is no feedback controll over the high-frequency roll-off. You can implement the entire filter characteristic in a single active filter which uses just one opamp. This helps to get more active signal control and reduces noise and the overall footprint of the PCB structure in order to avoid larger distances among all the devices and the possibility to introduce radiated magnetic interferences into the circuit. It is not convenient to use virtual grounding in order to avoid too much non-differential input signals. I have used two 18650 Li-Ion batteries for my phono amp project to have a good gounding. Due to their large capacities (3.5 Ah) I can operate the amp for houndreds of hours before I need to recharge them. I have integrated a battery cabinett at the back side of the amp which allows to change the batteries very easily to put them into a charger. So I don't need an additional power supply for the amp.

@Steven-pv1xr 13 күн бұрын

Great tecno facts. RIAA is for records and NAB is for tape they are excellent standards

@robjordan63 6 ай бұрын

Love the video, love the preamp; I built one myself, along with Rod's simple dual rail linear supply. Great combination!

@VIPINSAINI_20 6 ай бұрын

nice preamp, how you doing sir john, any updates on jat801

@JohnAudioTech 6 ай бұрын

I made some design changes to the 801 a year ago but have not pursued it since. I'd like to continue on the project at some point.

@VIPINSAINI_20 6 ай бұрын

@@JohnAudioTech good to here, is the change relateded to the miller cap or anything else,

@JohnAudioTech 6 ай бұрын

@@VIPINSAINI_20 Improving performance near clipping and possibly a "super beta" VAS amplifier.

@AnalogDude_ 6 ай бұрын

Cool, would you do video on the 39R and the 680nF next to the varistor from the VRDN schematic, I found some more schematics with this, i did a FFT in Ltspice, but i don't know what I'm looking at otherwise that dB levels and frequency are different if you change resistor and capacitors, what would be goal from such EMI filter or what are the legal requirements of this filter? I'm building a class AB amplifier on the PCB is on it's way, the power supply PCB is still to be designed and i want to include this. I watched some EMI video but it's mostly with switching supplies as subject, some talk bout YX capacitors, but not frequencies.

@jdekong3945 6 ай бұрын

What resistors manufacturer do you opt for in your audio projects John?

@JohnAudioTech 6 ай бұрын

Sorry, just saw this. I don't have a preferred brand but buy from a good source such as DigiKey to avoid the cheap Chinese junk. Unless inappropriate for the circuit, I use 1% metal film types in most projects.

@leneytunes 2 ай бұрын

Great explanation of RIAA stuff. Thanks.

@scottfreimann4820 6 ай бұрын

John, do you run a repair shop where a person could send in gear to be repaired?

@JohnAudioTech 6 ай бұрын

No repair shop. It is a hobby for me.

@bryanmcgivney3778 6 ай бұрын

I'd sure like to know who sent the board and parts to you? So i know where to send my money because i want a kit too.

@1pcfred 6 ай бұрын

Seems pretty decent.

@PU1JHA 3 ай бұрын

Rod´s projects are simple and the best circuits.

@Mikexception 2 ай бұрын

I watched carefuly shown by you RIAA curve (thanks) in compare to preamp test because I am curious abot why all pramps which I tested like two tube preamps, and three solid had own character. It is verty slight and doubtfull but I have my "top list" What I noticed that realy lowest and highest ends in your preamp are enough identical to notice theoreticaly in middle 2kHz-6kHz pramp has about 1 dB emphasis. This is fragile for hearing band. Depeding on performance of rest it could be correceed with tone controls

@nooruddinpanjwani8573 3 ай бұрын

You please show both sides of PCB. The circuit shows two ICs for one channel. And 5, 6, 7 are missing and pins 2, 3, 8, etc are repeated. Where as in your project it is 1 IC for one channel. There is confusion.

@JohnAudioTech 3 ай бұрын

The schematic shows two amplifiers (opamp) per channel. Each IC contains two opamps.

@stephenmeckley 5 ай бұрын

Does anyone have a DikiKey MyLists file for this project they can share?

@bob_mosavo 6 ай бұрын

Thanks 👍

@jedi-mic 6 ай бұрын

Try piggyback the op amps give you better sound stage more dynamic mid smoother mid-range especially if you put a 0.1uF across the Vcc + and- top one

@peterlarkin762 6 ай бұрын

Hi, do you mean parallel the outputs or literally add a second opamp on top of the first? I've played around with decoupling a LOT and find a 0.1uf across + - is not the best, and use 2 across each rail to ground at the opamp pin.