Project preamp hum. It also doesn't sound like RF.

Project preamp hum I thought that a hum would be caused by an AC ground. Sep 3, 2015 · When the turntable is not connected to the preamp i dont hear the buzz. Feb 1, 2019 · I am experiencing a problem with my turntable setup, well the project phono pre amp box. Feb 13, 2016 · This is a review and detailed measurements of the Project Pre BOX DS2. The phono cable is pre-installed at the turntable end therefore there is no Sep 20, 2024 · In this section, we’ll explore the two primary ways to reduce noise in your phono box setup: rumble and hum elimination techniques, and audio grounding and cabling solutions. Thanks guys, this preamp is a customer of mine and he has had it for years. If the turntable provides a 120Hz hum it might suggest that the amp’s hum is actually a 50Hz? Also, the turntable hum and audio bleed through doesn’t occur between PHONO and AUX/TUNER when a record is playing. The CNC or Mufsy is one I think is a SS preamp I would go for if I ever were to go SS. Between the neoprene washer which eliminated audible hum standing next to the table and reduced hum through the tonearm, and improved RCA cables which eliminated any hint of hum through the tonearm you can make an audible improvement in the TT for very little money. The high impedance 1/4" instrument input bypasses the microphone preamp circuitry to maintain a clean signal path. It is quiet but noticeable in the power amp, put bringing up the volume control (before the 1st preamp tube) makes it incredibly loud on both channels. Several problems where I am stuck: 1) Hum is 50 Hz, but should be 100 Hz if it came from power supply Dec 15, 2008 · If the problem was with the Grado, it would hum even off the record. Similar way as when measuring with AP Aug 18, 2020 · EAT and Pro-Ject are sister brands, and he explained that the Tube Box DS2's design exhibits parallels with the E-Glo Petit phono preamp [HFN Feb '19], which also mixes transistors and ECC83 tubes. In case your amplifier does not have a ground connection pin, most likely it does not have a phono-input (phono-preamp). Introduction This simple design has very low noise, close to the theoretical minimum, high hum rejection and <p>The ART Tube MP Project Series is a low noise microphone preamp that comes with a manual and power supply. I put the Hum Dinger upstream and the transformer became dead silent. Now four preamps in only a 2u rack and many problems with buzz! I'm trying to connect correctly all 0v and groundbut I have still many problems. Power supply from 50Hz mains transformer, bridge rectifier, filter caps etc, 300 v, 20 mA. At 1kHz, the noise density is about 3nV/rtHz, which isn't outstanding but isn't terrible. Once I unplug the phono preamp the hum goes away completely. I had one of the AC lines from the external step-down tranni connected to the enclosure. The solution: The turntable has a ground cable which connects to a screw at the back of the preamp. Also, PCB Feb 13, 2016 · This is a review and detailed measurements of the Pro-Ject Tube Box S2 phono preamplifier. . So is anyone familiar with these preamps and can suggest a common failure point in this section? Thanks The output signal from the preamp is fed into the comparator integrated circuit which will be used to create a pulse width modulated signal of the preamp audio signal. The change in signal level when switching from the -10 dBV setting to the higher gain +4dBu setting indicates the hum is part of the mic pre output stage noise. ” Grounding issues can be a common cause of this unwanted noise. FIX #2 May 25, 2020 · If so, make sure you are bypassing it before connecting it to yours. The noise is there right from start up and doesn't change despite Feb 10, 2024 · Hum is the same, here is a 1-min audio file of the preamp connected but powered off (some buzz), at around 10 seconds I switch the preamp on (buzz goes down somewhat but is still clearly audible), a few snaps in front of the mic to verify signal, then I shut off the preamp (buzz goes back up) and then remove the power cable (buzz disappears) at Jan 21, 2021 · I’m using Project’s MaiA DS2 as an amp (previously as a preamp as well). The whole unit was recapped and more within the last 5 years (not by me). Fosi Audio Box X2 Phono Preamp for Turntable MM Record Player Preamplifier with Gain Gear Stereo Tube Pre Amp Hi-Fi Mini Vacuum Pre-amplifier for Record Player with DC 12V Power Supply 4. woo hoo, it's a project! The makers have a nice web-page though , and Google shows that this preamp is on their facebook page. I have disconnected all turntable connections to the phono box and still the humming persists. The monitors are both 3 prong plugs to the outlet strip. One problem is hum. NOISE GONE! Yay! May 27, 2021 · So FYI. I Mar 20, 2013 · Still, the experiment seems to indicate that the hum is in your pre-amp if you can hear any hum (even at a low level) with the preamp input disconnected and output just going to the headphones. However, I will assume 250 ohms as my critical. I can't post any pics until later, but I'm wondering what the obvious diagnosis for this might be. - The hum is consistent no matter which input or tape monitor selection is selected. , every micro becomes a nano). Pro-Ject Turntable Electrical Hum owners manual, service manuals and schematics are for reference only and the Vinyl Engine bears no responsibility for errors or other inaccuracies. 0: A super low-noise MM/MD phono preamp," appeared in Elektor July/August 2016. Bessel switchable low-cut filter removes rumble and wind noise. Noise down -65dB wrt 1V means there's 500uV of noise at the output jacks. If the noise sounds like hum, try moving your turntable away from your amp. Apr 23, 2016 · The Project turntable connected to the preamp is also powered by a wall wart. I solved my hum by grounding the preamp to the screw on a wall socket. It also doesn't sound like RF. I have read that some tubes can be v noisy. If moving the preamp doesn’t help, you may need to get a new power supply or look into getting an isolation transformer. I recently bought a rather expensive isolation transformer to further adress this issue. Resist the urge to straighten them! By the way, I forgot to mention another "detail" of this phono preamplifier that I see somewhat problematic. I was going through the same thing you are. An external preamp could have been used, however implementing a built-in preamp would make our project an all-in-one audio amplifier. My question is, How do I set this up with least amount of hum noise, or any type of noise that will come from the mic input on my delta soundcard,which has a built in preamp,and the artube preamp? Apr 18, 2023 · Final Verdict. Jan 19, 2025 · I am working on my DIY Preamplifier new project based on the Elektor Preamplifier 2012 (Douglas Self) schematic. e. If the motor itself is noisy, a bit of oil might help. If you run the turntable motor with the cables disconnected and you don't have the hum, it is unrelated to the turntable power. In some rare occasions the hum can also disappear when the ground connection is disconnected. At the heart of the Pre Box DS is a pure single-ended Class-A output stage design, which is a real high-end option for such an affordable pre-amplifier. I was looking for some tube dampers and lifted the lid to realize, instantly, why this preamp had hummed. Gain is 40dB/1kHz. Bought a 1020a on ebay and 2 months later hooked up a TT and found BIG hum. I am trying to connect my Project Debut III TT to my Creek OBH-15 phono preamp which is connected to a sony receiver which I am using as an amplifier. Oct 28, 2016 · It performs much better than I had hoped for a first project (bar a couple of very small issues) but the most obvious problem affecting it is a low level 100hz hum. Phono Box DS2 is a highly flexible phono preamplifier that’s suitable for most cartridges on the market, MM & MC alike. Feb 15, 2025 · Hello, I recently picked up a wireless system (NuX B-2 2. It only disappears when I unplug the power supply. Interesting was I tried moving the wire that comes out of the turntable and goes into the phono preamp and the magnitude of the Hum varies. You could be over amplifying the signal causing noise and distortion. Jan 11, 2022 · After more research and reading how others solved turntable hum by replacing the interconnects between their turntable and phono preamp, I decided this was worth a try. The only way to get rid of that hum is to set the Gain 1 to high and the Gain 2 to low, but then I get distortion on loud bass. Aug 19, 2024 · Yeah, without that rumble filter those woofers are going to pump, especially on warped records. The First, check all the connections and make sure they are secure. Joined: 09 Sep 2008 12:12 am Posts: 14 Hello everybody. Oct 14, 2020 · The 12ax7 preamp I have is pretty quiet for a tube preamp with hum not noticable unless I really crank up the gain on it much higher than I need. Apr 6, 2018 · This is output referred noise- to convert it to input referred noise, divide the voltage noise density by 1000 (i. Feb 4, 2004 · New JFET Guitar Preamp Project Hello Opor, The BS170 is an Enhancement mode mosfet so the JFET circuit designs and methods described in this post will not apply without major bias changes. The main reason is because I encountered a noise problem with my DIY JCM 800 2204. It is on kind loan from a member and costs US $899 although I see some open box ones for US $699. 00 Current price is: $499. Soundwise its actually not bad, its actually somewhat a good balanced Preamp. Rumble and Hum Elimination Techniques. - to make sure its not my power amp, when I swap the preamps outputs to power the amp, the hum and quite channels will swap accordingly. The S2 costs US $399 on Amazon including Prime shipping. May 15, 2010 · These signals appear on the output of a tube phono preamp. Something to be said for getting the original circuit to work before changing things. Reproduction without prior permission or for financial gain is strictly prohibited. However, the main volume does not cause a noise Jan 2, 2019 · To combat this, I use the Audio by Van Alstine Hum Dinger - it completely eliminated hum in one amp, and reduced it slightly in another. Chassis for IEC, mains transformer. In this article, we will explore the concept of grounding in phono preamps and discuss methods … Phono preamp Grounding and Hum Read More » Oct 1, 2010 · OK I have a M-audio Delta 1010lt pci soundcard {8x8 unbalanced analog Ins/Outs,2 mic preamps or line inputs},ART Tube Mp project series/48v phantom power as my mic preamp,AKG perception 220 Condenser Mic. The other input is connected to a Sonos. I am trying to hook it up to an NE5532 based preamp, aliexpress XH-A901, but it has a terrible whine noise, which is not dependent on volume. May 2, 2012 · Pyle Phono Turntable Preamp - Mini Electronic Audio Stereo Phonograph Preamplifier with RCA Input, RCA Output & Low Noise Operation Powered by 12 Volt DC Adapter - PP999 , Black 4. A picture of the preamp is attached. I don't need the TONE and BALANCE control sections in my design, painted in Red in the picture below. I'm pretty sure it's the power supply at fault, as others mentioned replacing their power supply solved the issue. Jun 5, 2020 · Background hum at around 40% volume, increased as volume increases. After using several tube phono preamps I'll probably never go back to SS. By leveraging the high precision and low distortion of the INA117KU, this preamp maintains the integrity of your audio signal, making it suitable for professional audio Feb 15, 2025 · Project Author: Joined: 04 Aug 2008 2:22 am Posts: 386 Location: Denver, Colorado And it is the preamp the produce this hum. It plays well on low master levels. Switchable input impedance on the XLR in optimizes mic response. External power supply minimizes AC line noise and hum. I don't know a better place to ask then on an audiophiles forum. Cartridge, preamp, and cables are all that are in the signal path. He recently called me and told me radio sounds where playing when he switches to the Phono input on his Rouge Intergraded Tube amp. Return to “Pro-Ject Audio Systems” Apr 16, 2021 · In my previous (very old) video I described a way to eliminate AC hum from the phono stage by connecting a wire from the pre-amp's body directly to the Earth Aug 14, 2020 · Hiss is unlikely a ground loop (that would be hum). I remember it was noise coming from the tube. Very different to the amp’s own hum. but there 2 qwerks i found. I will directly connect the output of IC2A pin 1 into the input of IC9B pin 5 (Green traces). Does this mean it is the phono box that is broken, since I have eliminated all turntable input? just a constant loud humming buzz through the speakers, have tried Feb 9, 2017 · I have a debut carbon dc 3, bought new in 2020, when I first bought it it had a loud hum which the project ground-it power supply solved (makes sense since my amp uses a figure 8 power lead with no earth) but I was left with a quiet motor hum. It's amazing to see how much some companies have charged for Phono preamps in the past, well upwards of $3-5k for some of the bigger names. Aug 31, 2005 · The new ultra low noise discrete microphone preamp front end has a flat and wide frequency response and handles a wide range of input signal levels with a minimum of coloration according to the company. :( Thanks in advance, Morphy. But I have several new and old chokes hanging about, so maybe I should stick to that for now and see how the noise level is. I had badd hiss from a tube phono once and abandoned the project before solving it. So please try this step as well. View Product. com Feb 19, 2015 · In many cases, the hum is not actually electrical hum, it is motor noise due to poor isolation between the motor and the plinth. Oct 25, 2024 · The Original Project The phono preamplifier article, “Supra 2. May 24, 2006 · I had a hum with my new Project Debut III and phono preamp (TEC TC-778) and it turned out to be a simple issue- the power cord jack, which plugged into the back of the preamp, was making contact with the metal casing of the preamp and creating a hum. Please feel free Phono Box DS2 USB MM/MC Phono Preamp $ 849. Its “true” tube design offers a warm and rich sound that is sure to please audiophiles, and its compact size makes it easy to integrate into any system. SOLD OUT - Phono Box DS2 MM/MC Phono Preamp Elliot Sound Products “Project 66” is a low-noise, opamp-based preamp with a discreet front end. If that doesn’t work, try moving the preamp to a different location. Posted: 15 Feb 2009 7:13 pm . so i guess the preamp might be ok. Aug 1, 2018 · Before I get into the problem I’ve been having, my set-up consists of the Pro-Ject Debut Carbon DC with an Ortofon 2M Red cartridge -> Rega Fono Mini A2D preamp -> Pro-Ject Head Box S2 -> Sennheiser HD598 headphones. Output is capable to drive 50 ohm load, so one may directly connect headphones via 100 - 220 ohm pot. 3 out of 5 stars 5,804 200+ bought in past month Jul 29, 2017 · 4. The 47k/22uF B+ filter should do a pretty good job of power supply filtering, so I wouldn't suspect the B+ filter for now. It is on kind loan from a member. Every 63 seconds I get a popping/woodpecker kind of noise come through. Grounded everything no luck. ESP offers a PCB for this project which fits two discreet channels on a 65x65mm board. Neither the ART now my amp's built-in preamp have this issue. 6v c. I think the problem is a mechanical noise. 00 Original price was: $849. As it stands today, the preamp is dead silent in active mode at the highest volumes into sensitive speakers. I would google "ground stereo equipment" or something similar and try to follow the different steps in order to isolate the problem. It sounds Iike you're running through two preamp stages: the S2 and the built-in preamp inside your receiver. Sphinx Project Four. Towards the end of the '80's and into the early '90's, having a high end phono setup meant having a separate box for the phono preamp (in some instances a May 24, 2012 · Hello everyone, I'm new to this board. Maybe ask them ? Rebuilding it to get rid of the hum for fun and education is diy justification enough, It's not physically that complicated after all. Noise floor MM: 94dB (A weighted) at 40dB and 43dB input gain; Noise floor MC: 75dB (A weighted) at 60dB and 63dB input gain; THD MM: <0,01% at 40dB and 43dB input gain; THD MC: <0,05% at 60dB and 63dB input gain; RIAA-equalisation curve accuracy: 20Hz – 20kHz / max. Further, located on its own ‘island’ PCB, it is isolated so there is no noise pollution of the analogue stage. I don't think its ground loop and I have split the grounds - floating for amp board and ps and input/output jacks (OT)/pots. 0,4dB; Subsonic filter: at 20Hz with 12dB/octave; Input: 1 pair RCA/phono Elliott Sound Products Project 66 Low Noise Balanced Microphone Preamp By Phil Allison (Edited by Rod Elliott - ESP) Updated 17 May 2008 Please Note: PCBs are available for this project. t. See full list on hometheateracademy. May 25, 2006 · Hi, at the start two preamp in a 19p rack and two others. 5mV/5cm/s outputs, this should be well below the mechanical noises of playback. Jan 22, 2025 · This DIY audio preamp project using the INA117KU provides a simple, low-noise solution for amplifying weak audio signals, such as those from microphones or electric guitars. Once I separated the cables, the hum went away. 4 GHz) and I have a couple guitars with onboard pre amp fx (one is an fx knob one is an eq switch) and whenever I use the wireless system with these guitars I get a really loud high pitched noise, so loud my noise gate won’t even pick it up Mar 5, 2009 · 4) Same as 3 but this time the TT is switched on and Hum remains the same as 3. If I turn up the gain or play the strings very hard, I get a buzzing sound out of it. Just super clean +/- 12V DC. I've uploaded video to YT describing my problem (it was easier like that I guess). Click the image for details. Anyway, so I powered it up with a pure sine wave portable battery pack. It has a 50Hz hum and I have tried everything I know to solve the ground loop. Jun 9, 2014 · Hi All, I'm working on Sansui 1000 which has a hum problem. you may ask if i screwed the ground cable tight or correctly, which i tried many times, But the electrical hum is still there. Try connecting your S2 to a line-level input like an "Aux" or whatever it's labeled on your receiver. The 2SK117, however, is a JFET and may work very well as a project/experimental device. Anyway, I suspected the wall wart to be the culprit (cheap crap). I had begun to notice a sort of low rumbling hum during lead-ins, between Dec 27, 2012 · For those who might be interested, I have prepared an open project of the phono preamplifier for MM cartridge. May 2, 2023 · - pretty sure the hum is 120hz - Via headphones there really is no discernible hum in either channel. each preamp has a vtb9045(mic), vtb9046(line) and carnhill output transfo with mic Dec 20, 2015 · This seems to be quite a common issue with the Pro-Ject Essentials II turntable. Apr 26, 2020 · This is my Project S2, you can see the capacitors as they came from the factory. 8dB (line) Signal to noise ratio: 83dB (MM), 118dB (line) To purchase Project Four spares or Description. Oct 23, 2019 · I have a TPA3116 based board from Aliexpress, XH-M569, this board had some bad noise issues from an unnecessary opamp on the input, I removed this as suggested elsewhere and now it has acceptably low noise. I must this say this is the cutest tube audio product I have seen: A nice set of controls let you pick one Jul 9, 2023 · With serious levels of noise filtration, it performs at the level of well-designed LC filtering circuits as found in classic tube amplifiers. Enjoy! Oct 18, 2004 · A friend bought a soldano sp77 guitar preamp [ made in japan version ] that has a ground type hum bought it used this way , hum rises with master volume mostly independent of gain control , way too much to be normal , I separated the psu and signal ground point from the pcb and that helped , it is a. Jun 30, 2010 · Hi Guys, I am trying to setup a TT based system in my bedroom and encountered this strange problem with hum. Mar 1, 2022 · Should point out that the ‘ground hum’ noise is a proper ‘buzz’ as you described. Extremely Low Noise; Discrete Front End Up to 70dB of Clean, “Musical” Gain; High Output Signal Drive Capability; Fast FET Limiter to Prevent Overload Apr 11, 2020 · Hi there guys, I really need your help. There are also products made to eliminate ground loop hum such as Hum Eliminator and Hum X Voltage Hum Filter. My knowledge about this issue is really limited unfortunately. even though the ground from TT is connected to the ground in the preamp. $ 499. Notable Features: Uses a +/-15 power supply or two 9v batteries; 60dB of gain; Discreet, low-noise input stage; Accepts TL071 or compatible opamps The phono input on your receiver expects a low-level input directly from your turntable; it has an internal preamp. Measured EIN (Equivalent Input Noise) is -151dBV. Input connected to phono cartridge at idle. Jan 12, 2018 · Hi, I have a strange problem with my otherwise excellent ProJect Tube Box DS phono preamp. Original schematic of preamplifier was found in this article and slightly modified. After swapping four sets of cables from Audioquest, MIT, Tara Labs and Signal Cable making a test recording after each change…this swap did nothing to eliminate the hum. May 19, 2019 · The mani actually sounds better than what I was using (the project series ART preamp), so I'm hugely disappointing by this noise. It started after I added it to the system. I have eliminated the amp, speakers, turntable and cartridge. Sometimes the hum can be caused by interference from other electronic devices. It seems the TT wire acting like an antenna and whatever it captures that noise is getting amplified insdie the phono pre. It has very low noise and very low distortion. L R L R. For typical MC with 0. c. Push-button adjustment allows you to easily listen among load & capacitance settings, and front-panel gain simplifies things even further. In both cases, the 'headamp' is a low-noise J-FET stage with the first triode in cascode, leveraging a substantial 70dB overall gain. Nov 20, 2023 · But I have no impedance rating. I don't know if the pre-S2 models had the same DIP switches, but these certainly leave a lot to be desired. Stereo Preamplifier. Aug 14, 2020 · Some people apparently have issues with hum/noise because of the heater power supply, and some suggest adding a regulated heater power supply. Jan 22, 2014 · Changing to tighter fitting cables made another major improvement. I have decided to separate the power side and the signal side into different chassis' in the hope that this will help. With new capabilities and a stackable desktop enclosure, the Project Series version provides everything musicians have loved about the Tube MP for thirty years - and more. Conditioner has EMI/RFI filtering. add a review. Placement of tables and phono's has always been the same - never hum issues on either. There Jan 25, 2015 · For MMs, where not only the noise voltage counts but also the noise current, paralleling is rather counter productive and a single NE5534 will probabely show very similar noise figures at a fraction of the cost and effort. Transformes inside your amp may cause magnetic fields that are picked up by your cartridge resulting in a humming noise. It features a phase reverse and AM/FM band that makes it versatile and easy to use. Type "Project motor noise" into the search bar at the top of the page. I have a tube preamplifier with the power supply (rectifier tube) inside - the unit is noisy. This is a Kicad EDA project of electret microphone preamplifier for improving low-end electret microphone sound on a PC sound card. If this is the case use the turntables built-in phono preamp or an external phono-preamp. It is a professional audio equipment that is designed to enhance the sound quality of your music. If you have a power amp with 15dB of gain (which would be really low), then you have about 3mV of noise at the speaker jacks just being contributed by the preamp. 2-0. Cheers, Alec Jan 30, 2025 · Originally the preamp had a hum so it was shelved for quite a number of years. A small piece of electrical tape wrapped around the plugin solved the problem instantly. Feb 9, 2016 · A second interconnect has been used to run from the OUT terminals of the preamp to an input of the receiver (AUX of the Yamaha, or to Tape 1 of the Onkyo TX-82 at my work bench). Mar 25, 2021 · In order to remove this hum, try moving the power and RCA cables located around the turntable and receiver to see if the interference goes away. When it is switched to the Sonos there is no hum, when it is switched to the NAD phono preamp there is a noticeable hum, particularly when there is no music playing. Does the oscillation stop when you turn down any of the controls? Does it stop if you remove any of the preamp tubes? If the controls have little or no effect, try disconnecting the 4 ohm tap from the turret Jun 16, 2019 · At high gain settings the noise is limited by the EIN (Input Equivalent Noise), but at lower gain settings the noise is set by the output noise floor. Pro-Ject Tube Box S2 is a great choice for anyone looking for a high-quality and affordable preamp for their turntable. Intro It is a temptation to measure phono preamplifiers the same way as if it was a common link stage preamp, to drive it from very low generator impedance and to measure the preamp output voltage. filaments May 30, 2017 · Question 2) There's a noticeable hum, but it doesn't seem to be the motor hum people complain of - because the hum is there with the motor switched off and the turntable switched off. I once had a Dynaco preamp that I was using ad a phono stage hum when it had a bad component. There are very nice SS preamps though. It will be free to download for the two weeks following the publication of this news item. That's not great for a linestage. Unfortunately, it hummed louder than the amps. In some cases, simply putting thin rubber or neoprene washers on the Motor mounting screws is enough to stop the hum. Rumble and hum are two of the most common types of unwanted noise that can plague your phono box setup. The preamp is black Could be numerous things: TT, preamp, receiver, or even your house wiring (hopefully not this). 5. I had this issue with a power cable from a cassette deck causing hum on my turntable due to the cables crossing over each other. It is a multi-function device with USB DAC, headphone amplifier, analog pre-amplifier with Bluetooth, and phono stage. The preamp is made by ART and is suitable for use in studios or live performances. Feb 23, 2019 · Measuring noise and SINAD of MM phono preamps properly 1. Apr 18, 2020 · I should be able to reduce that noise by about 20dB. Nov 19, 2015 · From the preamp to the interface I'm using a 1/4" TRS cable that splits into tip and sleeve (Left and Right) going into the interface I notice a hum even when the turntable is completely off. So that means my lowest noise floor is 3 to 5 times that, so 750-1250 is my target load for the mic preamp . Set at 40Hz, it won't overly affect bass tonality. Top. It uses general purpose PNP transistor instead of germanium transistor. I get hum both with and without connections from the TT to the Pro-Ject. Input gain control and switch maximizes dynamic range of input and lets control how hard drive the tube. RME says its clip is +19 @ 12K ohms So my difference is 10db, then I add 10db for normal signal headroom. Gain: 25. Instead of plugging the X2 straight into MaiA, I now have it set up as X2 to Tube Box to Line 2 in MaiA, bypassing MaiA’s phono preamp stage. Features. Pyle Phono Turntable Preamp - Mini Electronic Audio Stereo Phonograph Preamplifier with RCA Input, RCA Output & Low Noise Operation Powered by 12 Volt DC Adapter - PP999 4. Built-in, low noise phantom power supply; Compact, stackable all-aluminum chassis; XLR and 1/4″ inputs and outputs; Phase invert switch; High cut filter switch; Variable input and output controls; TUBE MP Project Series Edition microphone preamp 1; 9V AC adapter 1; Three Year Limited Warranty (USA only) 1; Frequency Response 10Hz-40kHz, +/-1 Jun 13, 2009 · I'm getting closer to optimizing my pre-amp project. Looking for specific info? Sep 5, 2014 · To be extremely clear, this is motor induced hum, it's not ground loop 60 cycle hum, it is mechanical AC motor noise making it back to the arm and cartridge, and you will CLEARLY hear this annoying hum the second the stylus hits the record, between songs, during quiet passages, and at the end of the record, as the stylus tracks out, it's terrible. One of the thing what i‘ve discovered is, the Hum is noticeably loud during quiet part. The highly-shielded metal chassis also effectively rejects any vibration and electromagnetic noise, al May 24, 2012 · Don't move the ground for the input jacks to the star, that will increase the hum. Power amp seems clean. All components plugged into a power conditioner, which in turn is plugged into a voltage regulator. I had read that an inductor used there was a hum issue. 00. Nov 1, 2022 · Then as others have said . An example is mentioned here: This guide is to help you build the DOUK KSL-M77 Preamp clone kit. Mar 5, 2025 · Post subject: Simple 5687-based preamp, HUM, not just a little. 5 posts • Page 1 of 1. And check the mounting of the motor. I think it might be the ground connection thats the problem, i just simply touched the ground terminal on the TT and the noise reduces a lot. 2 out of 5 stars 6,104 Jun 19, 2019 · Pete - looking at the schematic again, I see what you mean. Without the pre, with only the 2A3 amp Nov 30, 2017 · OK, so what you've discovered, by finding out that the hum continues when the phono pre is plugged into the receiver, but without the turntable is plugged into the phono pre, is that the hum is definitely related to the phono pre itself and not coming from the turntable, so the turntable ground wire and induced cartridge noise are unrelated and nothing you do with respect to that is going to Jun 1, 2012 · The new ultra low noise discrete microphone preamp front end has an extremely flat and wide frequency response and handles a wide range of input signal levels with a minimum of coloration. . I also have an original black face slider preamp that was in my 1980 rhodes as part of a janus speaker system but it has a couple of mods on that have messed with the tone that After construction, the debug was mostly focused on removing hum, which was accomplished by careful earth-circuit ground connection on both the amplifier board and relay/capacitor board. Sep 30, 2015 · To my ears the pre's i like the most are the Peterson design I have on my 1972 suitcase and the low noise late mk2 preamp I have installed as a retrofit on my 1980 MK2. Nov 9, 2012 · this hum isn't present when my iphone is plugged directly to the amp, so the hum isn't coming from the amp the hum is still present when I turn my turntable off, so it's not coming from the TT I plugged the ground correctly from my turntable to the phono stage the hum is pretty loud specially in classical music since there are so many pauses So, I had this annoying hum/buzz with Pro-Ject Phono Box S2 Ultra. The hum gets louder as I turn up the volume. Mar 8, 2017 · Well this sucks. Prior to, TT straight into phono input on AVR - no buzz. Hooked the Tube Box S back to the original Project table, same XLO cables - now hum from Project, as well. 4 out of 5 stars 3,917 Jul 8, 2023 · When using a phono preamp to connect a turntable to an audio system, it is not uncommon to encounter a humming or buzzing noise known as “ground hum. I had bought my tubes from eBay, a small number of Russian frame grid triodes and possibly just a noisy batch. hubfc wiklonq nco plov bweng nnqwn jyxc ypgh kkxpl tnse ljqwzg zpanrnmz edqkjaruq lbuyvq myqpkxx