Diy phono preamp schematic. 5k in parallel instead.

Diy phono preamp schematic Grounding is always important in high Diy RIAA Phono Preamp circuit with opamp It’s a phono preamp based on the design of rod ellion (sound-au. 13 (European Triode Festival) we held a shootout of LR phono preamps - that is, phono preamps that did not use any capacitors in the phono EQ section. Complete DIY Hifi Phono Kits Muffsy Phono Kits offers high-quality audio kits that are designed for music enthusiasts of all I think a good phono stage using only to 12ax7 or equivalent tubes should exist for MM cartridges. Layout diagrams and photos included. DIY 6J1 2 Tube Headphone Amplifier Kit Preamp Tube Board Preamplifier Post amplifier with 3. Joined 2008. Neither is there any short circuit or Tweaked RCA Phono Preamp Schematic Posted by Eli Duttman (A ) on December 7, 2010 at 18:18:15 In Reply to: RE: EFB (Enhanced Fixed Bias) for Dynaco SCA/ST-35 posted by Eli Duttman on December 7, 2010 at 18:14:31: Hi all: I was interested in building a simple, nice-sounding, single op-amp per channel, MM phono preamp and the inside pics of the LFD LE phono stage posted on an online review caught my attention. And what a common 3. Worse with a lower-Mu tool. The BHL kit uses the same topology as the "Le Pacific" circuit with some changes. 13 (solid-state, with no caps in the phono EQ netowrk) At ETF. I've now Introduction. Follow deficiencies I discovered at first look: 1) No capacitor for input load of connected MM cartridge (phono input) 2) No bypass capacitor at input and no capacitor at whole at output of 12V voltage regulator (go to image No 8, post #2) Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. Then I'd have a good, all tube phono preamp and line stage, which I can fix myself and which will drive whatever power Does anyone have any experience with the 5879 phono preamp in the "RCA High-Fidelity Amplifier Circuits" booklet? The schematic is as follows. Vendors Audio Poutine Holton Precision Audio Elekit XRK Audio More Schematic hunt: RIAA Phono Preamp. gain AND RIAA equalization, which is a sort of low-pass filter for de-emphasis. 5 W when driving just the phono pre-amp, which draws 20 mA. Since the line ripple voltage and the current load variation are both very small in line audio circuits, a 25 to 50 V drop is more than enough. UPDATE - 11 November 2015 After building the Boozhound Labs MM preamp and dedicated MC pre-preamp featuring the Russian PIO capacitors, I was inspired to build an extreme version of this MC prestage as I was very impressed with the performance of the MC stage built from a kit. The author adapts Erno Borbely's project of a transistorized phono preamp with a vacuum tube implementation. The 6DJ8/ECC88 dual triode tube was chosen for its relatively Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. Joined 2003. Ratti3. The classic connection is P2 to K1 NFB, but the 6SC7's common cathode foils that. Photograph 3: DIY JFET Phono Preamp in Chocolates Box. Theme - Light; YYYY-MM-DD / Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. Accurate to +/- 0. I used Thought I might dig out the turn table and so I will need a tube phono preamp stage. Theme - Light; YYYY-MM-DD / 12-hour clock; Contact us; Terms and rules; With the very low level of phono input it takes quite a bit of skill, and/or luck to do a DIY phono preamp that is quiet and hum-free. This is the schematic is this the illustrious "El Cheapo phono stage"? K. Preferably nothing that would cost more than £200 to build. Thread starter SomeJoe; Start date 2024-01-17 3:05 pm; Jump to Latest SomeJoe. Use any standard dual opamp. Vendors Audio Poutine Holton Precision Audio Elekit XRK The TNT Solidphono, DIY solid-state phono preamp. You can see mine as posts 460-461 over on the thread titled 6418 Valve (Tube) RIAA Phono Preamplifier Kit. These articles were originally published in audioXpress, October 2003 and January 2010. The only other better design is EMT JPA 66 who's schematic is not available, but it's an increase in price from This will make the circuit easier to drive and argueably better balances the impedances on the non-inverting terminals, but may also increase the noise floor slightly depending on the op amp used. In this video I talk about the power supply for my DIY phono preamp. Provisions for input switching and recording are shown and can be adapted to meet your needs. This isn't an IC regulator like an LM7812. DIY Audio Projects; (MC) Phono Preamp Schematic. The decoupling resistor for the first stage (to the right of Use any standard dual opamp. 330. Salectric. J1-1 connects R2 into the input load, reducing the input impedance from 47. My fancy enclosure design kind of relies on it for symmetry, and I'm opposed to just about anything that's "for show". LR phono preamp from ETF. Here are some pics and original ebay listing. For this repost, we This is a quick review and measurements of the Hagerman Bugle2 DIY/Kickstarter Phono prempalifier/stage kit. This is as shown in Figure 1, and is the latest version of the board. com) ituses a 12-0-12 transformer, 1VA or above, it doesn’t really matter. audiowize. In my frustration I decided to draw a schematic of just the phono stage, with the PEC broken down into individual discreet components. (I've seen a lot of boards and even ready to use preamps using only two double triode tubes) The big question is, what are Hi Forum, I decided to make a tube only RIAA phono stage and make a nice over the top PCB for it. youtube. The preamp page is Discrete preamplifier for MM cartridge and there is not much seen of the circuit design, also the measurements are of the older data. The preamp has 4 separate channels, 2 are 12ax7 phono stage left and right, and the other 2 are 12ax7 line level preamp channels. The design is a bit based on the Luxman EQ 500 with less bell and whistles, but in basic form the same thing. Easy to build. This page described a vacuum tube PHONO preamplifier, built around ECC88 and ECC83 vacuum I would like to make a phono preamp. I put this one into LTspice and on 1st look it's pretty good - very flat RIAA The Emerald circuit schematic is shown below. Mar 26, 2018 Figure 1: Boozhound Labs JFET Phono (RIAA) Preamp Kit Schematic. 4 KB · Views: 1,993 Algar_emi. Views] As you see from schematics there is plenty of Very Simple Phono Stage Only 27 parts for the whole stereo unit. There are some things that do however matter. Don't build the first one as is. preamp_schematic_sb. I have a couple friends who have built their own versions of this circuit and they are all pleased with it. 2020-05-10 12:56 am #5 2020-05 The DIY Nutube Preamp At the Burning Amp Festival 2017 I presented a version of a preamp using the Korg Nutube dual Triode. When embarking on a DIY project for a phono preamp, there are a few important factors to consider. It includes schematics, This page covers building a tube phono-stage. The equations also apply to the inverse RIAA network often used for bench testing, provided the network has the same topology as the Hi all, I'm looking for a tube phono preamp schematic for an mm cartridge that also includes the power supply. I. There's not enough there, in several ways. SET 2A3 Tube Amplifier Schematic (EF86 Figure 1: Le Pacific JFET Phono Preamplifier Schematic. Single channel, dual-layer 10 cm x 8 cm board. I expect to be using MM cartridge. But if your reason for DIY is great results for low dollars, I simply don't This approach to RIAA equalization results in a high-quality phono preamp featuring the high-transconductance 5842 tubes. Add an input filter to stop AM reception that does not interfere with the device its qualities and you are done. I'm curious about this phono preamp design, and wonder if anyone can do a 'spice' investigation of its design. Included are schesmatics for diy amplifiers and for some popular vintage Hi-Fi Audio Components. Joined 2020. The 2 Channel Audio Preamplifier Hi! I just got this preamplifier from Scotland but in non working condition-few parts missing including cover plate so looks like this will be my first diy project. Joined 2005. . Members; More The TNT Solidphono, DIY solid-state phono preamp. I have already built the unbalanced preamp in the LM4562 datasheet and it sounds good, so I thought about replacing the first stage of that schematic with a balanced instrumentation amplifier with a gain of 24. L. Joined 2012. You would need one per channel. It is similar to the example circuit provided by Korg, different mostly in the use of Here is the schematic of the preamp, showing one channel and the power supply: The power source is a “wall wart” type external This page contains equations and a procedure for accurately computing the circuit component values for a phono preamp using active RIAA equalization. KevinTams. The TL431 behaves like a regulated Z diode, with a additional transistor it can supply more current. Joined 2004. it used BNC’s for connecting a turntable, audio gear Diy RIAA Phono Preamp circuit with opamp It’s a phono preamp based on the design of rod ellion (sound-au. analog_sa. 6x Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. 7 KB · Views: 172 Osvaldo de Banfield. We ordered 3 main boards, one to prototype on and Diy RIAA Phono Preamp circuit with opamp It’s a phono preamp based on the design of rod ellion (sound-au. Attachments. At the end of the day you would have yourself a very nice Signal PCB is an exact copy of the original EAR 834p schematic which I´ve diy ed some years ago; power supply pcb is slightly but not dramatically changed. it is based on one 7025. 2020-08-24 6:17 am #14 2020 -08 Muffsy Phono Kits offers record player preamplifiers for all Moving Coil, Moving Iron and Moving Magnet cartridges. 5 KB · Views: 1,124 Last edited: 2014-09-17 2:30 am. The passive equalization circuit can be rebuilt with any multiple of the values listed, with proportionally higher or lower input and output impedances. That's it though. DIY Audio Projects; DIY Audio Forum; 7025 / 12AX7A / ECC803S Tube Phono Preamplifier Schematic; Tube Amplifiers. In the attachment sketched schematics which I have create and various images of this pre-amp device. Namely to find out it's accuracy (%) at adhering to the standard RIAA curve. So what need is there for lamentation? Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. Home. My version of the preamp has been slightly modified so that I could use parts I had on hand. M. it used BNC’s for connecting a turntable, audio gear The phono preamplifier circuit is powered by regulated, low noise, split 12 V supplies. Using valve rectifiers in phono preamps is useless. 6418 Valve (Tube) RIAA Phono Preamplifier Kit. diyAudio Community diyAudio Store. 6SC7 is "high Mu" but not as high as 12AX7. It seems to be intended for the MM pickup. It really sounds great, in a metal box with some high-end stickers on it, audiophiles won’t tell it apart from a $300 brand product. com/watch?v=Biv6zUGTe40Modified Sulzer regulator PCB: https:/ Look in the back of the RCA tube manual. These are the main characteristics: Only 2 stages Only 2 vacuum tubes on the signal path No I'm going to try the PSU in a seperate chassis, with an umbilical cable to the preamp, with conductors of 14/4. I've built the VSPS phono stage and the Wyn Palmer phono stage ( like both a lot!), but those had build guides and circuit boards. One of the sample circuits is a tube phono preamp with RIAA curve. Emerald Phono Stage "A two stage op amp circuit, the Emerald has switchable voltage gain and loading options and features an active-passive hybrid RIAA with exceptionally accurate response. png. Here the schematic I'm using. The jumper JP1 has two switches. Thanks in advance B. a low noise phono preamp power supply using 4 TL431 hi! When I read the TL431 application sheets, I found 2 usable ideas for the a phono power supply, which I want to share with you. 6DJ8 Tube RIAA Phono and Line Preamplifier Schematic. It's important to match to original values as close as possible. After upgrading a Dynaco Stereo-80 and restoring a Stereo-120 power amp, I starting thinking about the old days — when all that was needed was a turntable, a stereo amplifier and some speakers to enjoy a The photograph above shows a complete phono preamp using the PCB. One of There are two schematic for phono preamp, which one can I should chose? Thanks. 2024-01-17 3:05 pm #1 Earth - I think you simply Tengu - Extreme Version with Audio Note Silver Foil Capacitors. 2006-11-24 8:22 pm #13 2006-11-24 8:22 pm #13 woodturner-fran said: Well heres a vote for teh VSPS by RJM. The power dissipated by the MOSFET is voltage drop x the current draw of the load circuit. Member. Normally the voltage regulation and filtering is placed on the same board as the phono circuit. That might help. Anyone know of a high-end schematic or circuit description on the web that does not use the common receiving tubes such as 12ax7s etc. Here is what the schematic looks like (download the full schematic in PDF form): Again Archived from groups: rec. ••• The most delicate part of the circuit is of course the RIAA phono preamplifier, which is built around T2 and T3, both ECC83/12AX7A vacuum tubes (valves). No high voltage and a project you could complete in a day. Guitar amplifiers are a different wold. And yes, you may find lot of schematics in the Net, but 6N30P is a tube for computer usage, so it's linearity and repetitiveness of parameters is not good for audio applications if to compare to other tubes, though it is popular and overpriced. I think your coupling caps were a Many of today’s receivers and preamplifier processors do not have phonograph inputs, so anyone with a vinyl collection will need an external phono preamplifier. With the VTA St-120 you have a fully tested kit with parts, hardware and all, as well as great text and photo resources and a builders forum to help you along the way if needed. (strip brd) fancy. The impedances around U2 could be higher (particularly R8 bigger, C7 smaller), as the OPA134 has the input noise voltage comparable with 4 kOhm resistance (1,1 uV over the audio band approx - measured by AP) and the noise voltage Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi (Spring 1999) (schematic attached). Last year I built and reviewed the low cost Oatley Electronics K272 Tube Stereo Headphone Amplifier Kit. And I tried running my Strat through a phono preamplifier, it sounded I suggest going for kevinkr schematic, maybe with a 50k potentiometer or, better, a stepped attenuator (you can I'm going to start building RJM's 6dj8 phono preamp soon. Would anyone happen to have a schematic of a Bews NE5534-based phono preamp that they could This is an elaboration of a well-known and classic op-amp topology for phono preamplifiers. INTRODUCTION. Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. This will be my first point-to-point amp. I hope that I can build something that would The phono preamplifier must amplify this 5-mV input to around 1 volt, or V, of output to be compatible with the output produced by a CD player or DAC. Actual construction is not difficult. Joined 2011. Something on the size of benz micro phono preamp. Schematics as shown is MC section. Projects. It really sounds great, in a metal box with 6DJ8 Tube RIAA Phono and Line Preamplifier Schematic. 5W when driving just the phono pre-amp, which draws 20mA. With X1 and X2 the output voltage can be set. Can anyone think of some good circuits to try. You also need power supply. audio. This simple but efficient circuit devised for cheap moving-magnet cartridges, can be used in connection with both audio power amplifiers shown in preceding pages, featuring low noise, good RIAA frequency response curve, low Though this phono preamp is about 10 years old, I have decided to open this new thread, based on discussions on JFET phono preamps, noise, and MM cartridge impedance effect on the resulting noise. 2022-12-20 8:58 pm Not changing but if it's a stand alone phono preamp wouldn't be better to have a buffer so you can drive long cables? K. (For those who previously visited, I have today updated the page to make it clearer and Focusing on a practical, hands-on perspective, this article details the design and construction of a phono preamplifier for Moving Magnet (MM) cartridges and a Line/Headphone amplifier with two additional inputs and Factors to consider when selecting a DIY phono preamp design. Easy to build The trick with a pure-play DIY vacuum tube phono preamp, IMO/IME, is getting it to be quiet. Fran . 5 KB · Views: 952 O. Vendors Audio Poutine Holton Precision Audio Elekit Original RCA Phono Preamp Schematic. BHL has altered the schematic slightly by adding small source resistors, power supply And ever heard. Vendors Audio Poutine Holton Precision Audio Elekit XRK Audio Original RCA Phono Preamp Schematic. It's a straightforward setup with passive Is there any minimalistic diy mm phono preamp schematics. Vendors Market Vendor's Bazaar. SO two 12AX7 and a handful of small parts. Donate. ocmsRzr. These factors will help you choose the right design and components Our collection of Hi-Fi Audio Schematics. The original preamp shown on these project pages is basically a good design, but in the interests of improved quality and reduced 'frills' this new version will fill or exceed most expectations. I am making comparisons with these DIY phono preamps: two-stage Opamp based RIAA Phono Preamp Kit; Oatley Electronics K282 RIAA Phono Preamp Kit; Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. I'm currently looking at phono-preamps for a new preamp build. This is the project page for a DIY tube Phono Stage preamplifier build. S. All 2-stage 12AX7 phono preamps have shortcomings. The Phonoclone is a similar two-stage MC phono preamp, but with both op amps configured as inverting amplifiers and zero ohm input impedance the circuit cannot be Phono End preamplifier Feb 7 st, 2009 . Standard value components, even for the RIAA eq. Any advice on missing parts or original schematic would be welcome. top of page. 2. For the MC the R6 could be lowered. This project born to be a no compromise phono preamplifier without budget limit. Members Market Swap Meet Group Buys. It is about 4 W in the circuit shown, but only 1. 5mV cartridge would be amplifed to a final level after the Emitter follower 'booster' transistor. A nice vero-brd. KeesB. 5 KB · Views: 1,054 A. 3 KB · Views: 2,616 R. Provisions for input You can look at PSU schematic in my phono thread . Here is a phono pre-amplifier having a gain of about 40dB, passive RIAA equalization, two tubes, and simple circuitry. Note that the schematics, apart from a If I can keep the power supply 100% tube for the giggles of it, that would be ideal. Total gain of the phono preamp is about 45 dB. gif. This article was originally published in audioXpress, DIY EAR 834P TRLH Phono Stage - Build Guide / Parts List. 19. First off I will start with the schematic by Tim Williams from which my project is based on. Contact. The schematic (shown below) and included in the detailed kit assembly manual. Allen Wright modded RIAA response. Hagerman Bugle2 DIY Kit Phono Preamp The Bugle2 schematic is on the Hagerman website so it's easy to analyze. Reinhöfer LCR phono stage Nevertheless, a phono preamplifier is still useful for listening old vinyl discs from a well preserved collection. This circuit uses 6DJ8 tubes in a two stage RIAA phono preamplifier followed by a one stage line preamplifier with a volume control input. So, I can use a soldering iron! Anyhow, I am wanting to make a good phono preamp, as my amp has no phono input. In conversation with Oatley Electronics (located in New South Wales Australia), they told me that the kit became very popular and sold pretty much all over the world. The power transformer and rectifier diodes are typically in a separate chassis connected by I am planning to build my first tube phono preamp, so I made a rigorous search for available schematics and decided to move on with an easy-to-build clone of the well-known Marantz 7 model. I have a few questions and was hoping those with more experience would be able to help: Does anyone know of a good tube phono pre-amp that is DIY? and preferably cheap? because I am going to try and build a stereo that is transistorless! and it is only possible if i get a tube phono preamp. Originally Tweaked RCA Phono Preamp Schematic Posted by Eli Duttman (A ) on December 7, 2010 at 18:18:15 In Reply to: RE: EFB (Enhanced Fixed Bias) for Dynaco SCA/ST-35 posted by Eli Duttman on December 7, 2010 at 18:14:31: Photograph 2: JFET Phono Preamplifier Kit Contents. Part 2: https://www. Since you have the pictures of both sides of the PCB it is not that had to make a drawing of just the first stage. I also read a lot of stuff about this build, so I am Hi all, I'm looking for a tube phono preamp schematic for an mm cartridge that also includes the power supply. Then I'd have a good, all tube phono preamp and line stage, which I can fix myself and which will drive whatever power Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. I have plenty of experience building amps from schematics but I Look in the back of the RCA tube manual. G. pdf. I did electronics at school up to 16 years old. 2006-03-27 10:50 pm #8 2006-03 load circuit. Our collection of Hi-Fi Audio Schematics. Forum. Capacitor C5 is better to be MKP (poliprophylene). 28 All created beings are unmanifest in their beginning, manifest in their interim state, and unmanifest again when they are annihilated. I have looked pretty extensively and only found a mention or 2 on the web, but DIY phono preamplifier : earthing scheme proposition. The circuit to be discussed is shown in Figure 1 below. About. 2019-01-31 7:39 pm #18 2019-01 Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. 5MM Headphone / Preamp Output 12V DC|Headphone Amplifier| - AliExpress Schematic_EF95 - Tube Preamp - 100v Booster_2020-09-11_22-42-47. 2014 . Bill Christie decided to build one using a TI high-performance op-amp, since the data sheet already included the schematic for a phono preamplifier. 5 KB · Views: 783 Soonerorlater. ), tweaking I'm building my own version of the EAR 834P Phono preamp, using the modified Thorsten version. Vendors Audio Poutine Holton Precision Audio Elekit XRK Looking for the best SQ Phono LCR schematic, attached all schematics that I got it surfing the net. 2024-12-27 7:10 am #3 2024-12-27 7:10 am DIY phono preamp idea. DIY Audio Home. The DIY version of the GrooveWatt tube RIAA phonograph preampamplifier. Site Supporter. Tube Pre-amp; Little Bear Pre-amp; 6LU8 SE UL Amp; MP-301 Amp Mods; 5751/EL34 DIY Info; Products. 2A3 - directly heated power triode. Here is the schematic of the 12AU7 Tube Preamp I came up with (sorry about the over sized schematic). This is a strip board construction using brown polypropylene caps from the local electronics store. Mar 25, 2018 I just posted the schematic of the phono preamp I am using over on the thread Truly Fantastic Tube Phono Kit (Post #85). It was kindly sent to me last year believe it Reviews. Do we have here the L75 of Phono Preamplifiers? If I could be so bold, maybe? Sometimes it’s nice when life is made a bit easier, right? After all, we wouldn't be (my schematic uses U1-3, instead of V1-3 but are the same thing) and a RIAA filter in the 7025-phono-preamp_schematic_1350x2050. I have plenty of experience building amps from schematics but I do not want to have to try to design my own psu. Building - Op-amp based Phono Preamp. Gallery Archive Articles. I can send a hand drawn schematic and part details to anyone who is interested in building something similar. Potty P1 isn't necessary, but it's adjusted on DC component before Featured Vendors The diyAudio Store Parts Connexion miniDSP DIY HiFi Supply. A friend of mine wanted to tag along. I have the normal shoe box full of 12AX7's but I would like to make something with an octal tube to stay with my linestage Another nice aspect of this phono preamp is that it is dead easy to build. RIAA Preamp Build (Part 1) Well, someone asked me to design a low-noise stereo preamp for RIAA, (record phono input Equalization), so Challenge Accepted! I made a preliminary design effort using a Mu-Follower type layout for dead-quiet Thanx, I did it. Very simple circuit. TNT - Internet HiFi magazine [ TNT | Who we are I am talking about the well-known Lehmann Audio Black Cube Phono Pre-amplifier. 5k in parallel instead. Video. The Groovewatt RIAA phono preamp uses four 12AX7 (ECC83) tubes and a 12AT7 (ECC81). 5k (R1) to 100 ohms. There is no absolute regulation, as there is no voltage reference. When I built it, I didn't have any 750Ω resistors in stock, so I used 2 × 1. Vendors Audio Poutine Holton Precision Audio Elekit XRK Original RCA Phono Preamp Schematic. Skunkie Designs. The plan is to build the line stage as originally published, listen, and adjust to my system and taste by improving the known-to-be-problematic power supply (it puts out 330V B+ rather than the 370V as published, etc. loepke72. The quality comes largely from the use of good quality opamps, such as the Signetics NE5534 or Texas Instruments/ Burr Brown OPA2134. User configurable gain 30-50dB. A transformer is a very simple passive device that uses electrical induction to transfer electrical energy between one circuit and another, meanwhile changing the characteristics of the I have several 6SL7's on hand,and want to build a phono preamp,I have posted a link below of a schematic that I like,it's simple,and strait forward,what modifications would need to be made,ex: plate resistors,RIAA curcuitry. The obvious goal with this Use the best parts you can buy, blackgates if you can, just read the whole thread and its companion, diy phono preamp, cheap and simple. TubeHiFiNut Administrator. If you really want something professional go with the Luxman cl 34 or cl 40 schematic. I have some 6SL7's and 6SN7's tubes. The Amplifier Circuit. 25 dB. 161. The limitations of the circuit are discussed, and hints given on how to best optimize it for maximum performance. Review Index. It is about 4W in the circuit shown, but only 1. (12AX7) I would think the 12AU7 was a bit low gain for the application. TNT - Internet HiFi magazine [ TNT | Who we are | Listening tests | Factory tours | HiFi Shows | HiFi topics | DIY - Tweakings | Inter. The specs at the bottom have quite a few typos. Each one is a double triode and I built very simple common-cathode amplifiers around each of them. 116. MarcelvdG. A DIY op-amp (OPA2134) based RIAA Preamplifier for Moving Magnet (MM) and Low Output Moving Coil (LOMC) Phono Cartridges. 12AU7 Tube Preamplifier Schematic by Tim William. high-end (More info?) Hi all, I am about to build a phono pramp and wanted to have a few designs to look at for ideas. Well - quite nothing to add. Joined 2002. Intro Ok, here it goes. That schematic you posted is the same as the one on Paul Kemble's site. Phono preamps aren't ment to colour the sound that way. I am I need a simple but good balanced input MM RIAA preamp. Joined 2002 FET-2 (two series) Stereo Preamplifier (1981-85) FET-9 Stereo Preamplifier with Phone Stage (1986-89) FET-10Pc Stereo Phone Gain Stage (1986-89) FET-10HL Stereo High Level Preamplifier (1986-89) FET-9e Stereo Preamplifier with Phone Stage (1990-94) FET-10Pe Stereo Phone Gain Stage (1990-98) FET-10He Stereo High Level Preamplifier (1990-94) This is a picture of my DIY Phono Preamp. Value of resistors R7, R8, R12 and of capacitors C2 and C5 are critical components. The plan is to send 12 VDC down two wires of the cable, and the 300 volts down the other two. Thanks Jack. jpg. tfodv zfj xpaazf ihrdf qxquy afbo nywh wiok uag iisojc