Search the Community

Showing results for tags 'Passive'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • CLASSIFIEDS
    • Private HiFi Classifieds
    • Music For Sale
    • Classifieds - Non Hifi Related
    • Ebay Links
    • Spirit of the Wam
    • Sold Items
  • 2 CHANNEL
    • 2 Channel
    • DIY
    • Owners Clubs and Forums
    • Headphones
    • Home Cinema and Audio Visual
    • Computer based HiFi
    • Tech Corner
  • WAM BAKE-OFFS | KEGWORTH
    • THE WAM HIFI SHOW 14 - 15 March 2020
    • THE WAM HIFI SHOW 2019
    • WAM Bake Offs
    • WAM Shows Archive
  • MUSIC
    • Genres
    • Recorded Music
    • Gigs and Concerts
  • REVIEWS
    • Product Reviews by members
    • My Set Up At Home
  • MANUFACTURERS | DISTRIBUTORS | RETAILERS
    • Trade News, Reviews, Advice & Discussions
    • Trade Classifieds
    • New Products and HiFi Start Ups
  • THE WAM ARMS
    • Our Public Bar
  • OTHER HOBBIES
    • Photography
    • Sports
    • Cars, Bikes & In-Car Entertainment
    • Food & Drink
    • Books, TV & Films
  • CONTACT US
    • Acceptable Use Policy
  • Linn Owners Club and Forum's Troubleshooting
  • Linn Owners Club and Forum's Initial Linn Owners Welcome To Wam Thread
  • Linn Owners Club and Forum's Discussions About Old Linn Forum
  • Linn Owners Club and Forum's Hi-Fi Separates and Components
  • Linn Owners Club and Forum's Turntables & Record Players: Linn Sondek LP12
  • Linn Owners Club and Forum's Network Music Players & Music Streamers
  • EAR (Esoteric Audio Research) Owners Club and Forum's Topics
  • Michell Owners Club and Forum's Michell Engineering products
  • PMC Owners Club and Forum's PMC Louspeakers

Product Groups

  • Private Members & Megastore Subscriptions
  • Trade Members & Megastore Subscriptions
  • Wigwam Shop
    • Polo Shirts
    • Fleeces
    • T Shirts
  • The Scalford Hifi Show Tickets
  • Harrogate Home HiFi Show Tickets
  • THE WAM HIFI SHOW 2018 TICKETS

Blogs

There are no results to display.

There are no results to display.

Marker Groups

There are no results to display.


Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


Location


Real Name


Turn Table


Tone Arm & Cartridge


SUT / Phono Stage


Digital Source 1


Digital Source 2


DAC


Integrated Amp


Pre-Amp


Power Amp/s


My Speakers


Headphones


Trade Status

Found 7 results

  1. Ok, so in my dreams... anyone wishing to talk about a particular active product would take this diagram and either draw a boundary on it or highlight in a colour of their choice the components which are included in eg a Dutch&Dutch system, a Linn Exaktbox system or whatever. These are a generic passive loudspeaker system and a generic active loudspeaker system; I have drawn on ATC's offerings as off-the-shelf examples with which I'm familiar. Basically, the critical aspect here is the sequence of connection. Are these examples crystal clear as a starting point? If so, the challenge is to draw an equally simple schematic to describe other topologies or specific brand/models. An opportunity to simplify and communicate not to willy-wave about size or number of boxes!
  2. I have a MINT passive preamp (line stage) for sale, due to an upgrade in my system. Music First Classic V2 Copper , date 24/10/2016, serial number 7156 It is in immaculate, mint state, stunning! see the single ended/balanced in and outputs on the pictures. Looking for 1.800,- GBP, a bargain for one of the best audio devices i heard in my live HUGE PRICE DROP ONLY 1.500,- pounds, FREE SHIPPING Ships from Brussels, Belgium, where I live.
  3. I need to have a “spring clean” ! I purchased this from take5 in 2014 and have been using it quite successfully with a variety of valve power amplifiers in my system. However system changes have meant that it is now surplus to requirements and the time has come to part company. I believe this to be a factory-built example and the photographs demonstrate that it is in excellent condition. It has 3 x RCA or 2 x XLR inputs, 1 RCA or 2 x XLR outputs and two gain settings. I have only used RCA in/out so cannot vouch for the XLR connections. Measurements - 36 cm wide x 32 cm deep (including posts) x 12 cm high (including feet). Volume control is stepped with 24 steps. I do not know which make of transformers are fitted. I have taken one out but there is no name/identification of any sort on it. Maybe someone can identify them from the photograph ? From Gizza's post below " the transformers are the Silk Audio Supermalloys, I came across Brian's original sale posting whilst looking for reviews and info. DIY HIFI SUPPLY introduced these as their top of the range when Stevens and Billington stopped supplying theirs to other manufacturers. The reviews I read said they were not far behind the S&B at all." I am looking for £400 plus p/p at cost, although I would much prefer collection from Linslade, Beds, LU7. I could demonstrate then if required. http:// http:// http:// http:// http://
  4. With the Reviews section in abeyance I thought I would still go ahead and give you my thoughts on the little Khozmo passive preamplifier: It was twenty years ago that Sgt Pepper taught the band to play…… Well it was actually 34 years ago (yes 34 years!!) that CD hit the (audio) world. It brought a whole range of plusses and minuses that have been worked on for the last 34 years. Real progress has been made. It took some time but it has become the mainstay of music delivery even though now it is being overtaken by streaming. One of the possible plusses involves the audio bit of the DAC. Nearly all DACs use opamps or discrete components that provide an output of 2V. This has become an unofficial standard, although the XLR variant gives 4V. With power amplifiers requiring about 1V for full output this allows a change in the role of the preamplifier. If the output of CD/DACs was 2V and the power amplifier required 1V then all that was needed was to attenuate the output signal down to 1V or less. This brought about the possibility of using very simple single/two component (preamplifier with no amplification) attenuators. The birth of the passive preamplifier/attenuator. Making the thing less hair shirt some added source switching and heaven forbid……..remote control. Now this brought great promise. There would only be 1/2 components between the DAC and the power amp. How could it get any better? Stunning sound quality, cheap costs and every one would be smiling, bar preamp manufacturers. But it did not work out that way. Everyone and their dog built a pot in a box, one set of input and output connectors and stunning sound flowed………er not quite………or not always. For me I saw this happening and bought a CD player with the volume control built into the CD player itself. It had a digital volume controller. How could anything go wrong? It did and I preferred my active preamplifier. In fact, the in-built volume controller sounded terrible. Why? Well despite the great promise, the volume controller worked by ‘decimating’ the signal. It reduced the volume by chopping off some bits. Awful. They have got better now. OK along comes Creek who actually put together what I regard as a cracking item, the OBH 22 preamplifier. It has three inputs and two outputs. A source selector, a volume control and used a high quality Blue Alps pot, all with a natty remote control. With my ARC valves it required a really brilliant preamp to sound better. All it would do that was negative was to lose some bass impact and soften the overall dynamics. But it was incredibly natural, ultra-detailed and very easy to listen to even on rock music. However, occasionally it just did not work with some equipment and it sounded soft and quite mushy. Not often but it required care in matching impedances. Using long interconnects between the attenuator and the power amp could lead to problems. But taking care to keep interconnects short (1m) then all was OK. However, it is no more as Creek do not make them anymore. A pity. Recently there has been a huge interest in passive attenuators and that has produced many variations on a theme. There are many simple pots in a box. There are more sophisticated step attenuators where individual resistors are soldered onto the volume controllers and instead of the volume being continuously variable it is attenuated in steps. There are variations of even this type including shunt attenuators where one resistor is always in circuit and another is used to provide the steps of the volume control. There are Light Dependent Resistors where a change in the voltage of a small light source affects the LDR, it changes its resistance and it is connected to the output volume. And of course there are transformers that attenuate the signal either through Transformer Volume Controllers (TVC) or auto-formers. As you may expect all have their advocates. I am looking at the Khozmo Passive Preamplifier (Attenuator), which is a stepped shunt attenuator. This is a company I have not come across before. They are based in Poland and you buy direct from them via the internet. This is something that is becoming more common and promises to give good products at a reasonable price as the mark-ups from the distributer/shop are not added into the price. However, you have to buy blind and rely on any money back promises and reviews like this one and people’s experiences. It is possible to buy this shunt attenuator with different quality resistors for both the shunt resistor and the switched-in resistors. Khozmo sells the standard attenuator with Caddock and Vishay resistors with upgrades possible to the Takman Rex and Vishay Z foil resistors. They are sold with either 10/20/50/100/200Kohm input impedance and in my case the 10K variant was recommended as I was using it with the Nord Class D power amplifier. The attenuator goes from -60 to 0dB in 48 steps (2dB increments from 1-11 and 1dB from 12-48) with make-before-break switches, hard-gold contacts, ±0.1dB channel matching, just two resistors in the signal path at any given setting, CNC-machined PA11 aluminium bodies and a precision ball-bearing support. Everything is hard wired with solid silver core wire. Because I listen slightly off centre I asked for the dual mono version which is slightly less convenient than using a stereo version but you do get control over the balance. My attenuator had three input and two output with phono connections (which led to an odd problem later). The box is very well made. It is quite weighty and looks the part with wooden cheeks and the controls have a nice solid feel. Overall, including the attenuators, it is well-built and it is hand made to boot. If you buy the stereo version, it can be remotely controlled at extra cost. The really good news is the basic model costs $300. My model cost $400 which with postage made a landed priced of £320. So how did it sound? Well I wanted to use it with my Auralic/Aries+Audionote DAC2.1x front end, the Nord Class D power amp and Audionote E/HE speakers. I therefore had an issue with the power amp needing XLRs and the Khozmo I bought using phonos. Maybe I should have got the XLR variant. Anyway in goes two amorphous make XLR/Phono adaptors and I get a sound out that it is very good. But I can surely do better with a Cardas XLR adaptor? I buy a pair and things did not work out. So eventually I go for the Neutrik XLR/phono adaptor and all is now well. Well enough prevarication how did it damn well sound? Well as you may expect from having just a couple of resistors in the circuit extremely neutral and natural. The 3D soundstage is big and it has great width and depth and dare I say it height. It also shows up a lot of studio recordings as being very dry and artificial with their limited soundstages. I used the old demo favourite of Misa Criolla featuring Mercedes Sosa and you can hear the large acoustic it was recorded in and the echo fading away. As you may expect there is no noise coming from the speakers with a passive attenuator and an extremely low noise power amplifier. You can therefore easily hear the echo from the acoustic as it gently fades down to zero with no cut-off. The bass was big and powerful with no overhang. The bass tonality was very good. It was possible to easily hear the different types of bass and the tricks done in studios. Onto something musically different, Dystopian Overture from the new Dream Theater album in 24/96. The tricks used in this studio creation were easy to hear and very clear. In the middle of this track there is ‘kitchen sink’ moment where all sort of instruments are added and taken out of the mix. Their different added echo and layering is easy to hear. After listening to that section of music it feels like you have been on an audio assault course. You have been overwhelmed and given a feeling of being taken over which may have been what the band wanted to paint for this desolate future. Other preamps can become confused by this passage making it messy and less unnerving. Of course it is not perfect. Despite using high quality resistors the dynamics are not as sharp as those from active preamps and the high frequencies do not have the air of transformers or active preamps. Active preamps still have that huge drive and attack and this resistor based attenuator is a little softer. But for me it is more relaxed and easier to hear for longer periods of time. Maybe not as showy. If you are concerned about whether everything will work and need to check the impedances Arek is great with advice and always responded to my e-mails very quickly and allows return of the product if it does not work out for you, within a reasonable time period. In conclusion given that some of the other preamplifiers I used (Nuforce P9 active preamplifier, Audionote M6, Creek OBH 22) were far more expensive than the little Khozmo and it was not embarrassed or shown to be deficient apart from a few minor areas makes it a bit of a bargain. It is highly recommended and you can get any variant you want. So let me introduce to you The one and only……….Khozmo…..
  5. maz06

    SALE NVA P50 Passive Pre Amp

    NVA P50 Passive Pre-Amp. Fantastic little passive pre-amp, much better than its low price may suggest. In Excellent condition, slight scratch on the volume knob. This was partnered my Quad 306 power amp which is also for sale. NVA P50 Specifications: · Controls - Volume and source select · Inputs - Four line level and direct · Output - Three pairs of 'pre-outs' for single / bi / tri amp support - plus tape output · Dimensions - w250mm x h70mm x d210mm £125 – ONO Collection Preferred - Greater Manchester
  6. Looking for a Music First Classic V2 Copper, pre-owned. If anybody? Let me know! Thanks
  7. I would like to provide my thoughts on the Glass house TVC passive pre-amp I purchased recently on the Wam. In recent years I have tried many different active valve and transistor preamps as well as passive preamps with my Net Audio modified Quad 405. Most of the passive preamps resulted in a revealing but slightly clinical sound, in many cases with a loss of timing so the performers sounded as if they were dragging their feet. The exception to this was a MFA Classic which had a bit more body but had too much gain for my amp and speakers at the time. So I always ended up reverting to my Quad 34 which although veiled and less detailed sounded more energetic. However I have always thought I wasn't extracting the full capability of the Quad 405 which can sound excellent when partnered sympathetically. MFA still use a Quad 405-2 in their demos and at the recent Whittlebury show produced the best sound of the day (IMO) feeding some Graham Audio LS 5/9s. So as I don't give up easy (some might say bloody minded, I couldn't possibly comment....), I recently purchased a Glass house TVC hoping to capture some of the sonic signature of the MFA Classic I sold. The model I've purchased has the top of range C-core Transformers and all the option boxes ticked so it has upgraded switches, wiring and sockets. First impressions as I unpacked it was that it is about twice the size I was expecting, and it is quite bulky and heavy. The internals seem well laid out and of high quality. This example was built up by the factory and the soldering and assembly seems clean and tidy. For such a big case the socketry is very crowded due to the blanking plugs for the XLR equipped model which shares the same back panel. A bespoke panel for each model would have been much nicer. The casework seems more solid if not as professionally finished as the MFA. The paintwork on the cover seems a little uneven though I think the case is alloy which may explain it. However, it is certainly better than some Chinese made valve amp products I wont mention. Overall, build quality seems good for a kit but of course is not in the same league as established high street brands. It certainly doesn't exude much in the pride of ownership stakes, however at least at looks discreet when placed in the rack. Operationally the volume control on selector switch are nice to use and positive however there is an annoying pop when switching away from some sources, for example a CDP. This can be avoided by turning the volume down however a mute toggle switch would be useful both when switching sources and for startup. Finally, the other black mark in my book is the poor design of the volume control. The shaft of the control knob doesn't mate cleanly to the shaft of the stepped switch. This puts lateral pressure on the volume control shaft as it passes through the brass bush in the fascia resulting in a stiff action. To partially counter this the stepped switch is mounted on a bracket that flexes. It took a considerable time to realign the various components to get a smooth action to the volume control. A much more professional solution would be to use a nylon universal joint or similar to connect the shafts together. Sonically this TVC preamp is unlike other passives I have tried. Gone is the revealing but dry presentation replaced by a warmer yet insightful sound. Notes sound slightly rounder and fuller but without a loss of pace and rhythm. The soundstage is also more generous. The result is a forgiving sound that works well with all material. If anything it is more like a revealing tube preamp without being too obviously coloured. Unlike most passives, it also seems to add a little presence and scale that seems to extract the best from less well recorded pop and rock. It is also very good at extracting detail including background vocals and ambiance that were disguised before. Little cues such as intake of breath are all captured but not the expense of musicality. Compared to a highend transistor preamp bass it is not as deep or rapid fire quick. It doesn't compress or lose pace and still sounds good playing AC/DC but it does lack the last degree in attack of a ballsy highend transistor pre where the leading edges are more pronounced. On any other material it is as good, or better, than other preamp I have heard in my system. Top end is extended and airy with no sibilance, mid range has real presence and bass is full and textured so drums sound like skins rather then cardboard boxes. As mentioned the only real area where it doesn't excel is that drum bass could start and stop a bit quicker. I cannot try it with any other power amp as I only have the Quads, but I can say that it is an excellent match for the venerable Quad 405. And with my current speakers I can use almost the full range of the volume control so there are no problems with gain. As considerable changes have been made to my system over the period, it is hard to say if it betters the MFA or otherwise, however I believe it to be at least comparable. It seems a little fuller sounding than the MFA Classic, so I would imagine that the final choice would depend on the balance of ones system. However it is certainly cheaper, so gives one the opportunity to try a quality TVC passive for a lower outlay. So in summary I am delighted with this preamp, which has taken my system to the next level at a modest cost. Thanks again to Bosa for a very easy sale.