Welcome to bid for Variable Audio Attenuators for Valve and Vintage Amplifiers This auction is for brand new device developed to match accurately audio signal levels in between modern signal sources, like CD/DVD/DAB and old school higher sensitivity amplifiers, valve ones in particular. The device is capable improve quality of sound reproduction in nearly any system. We offer here one pair of attenuators for a stereo amplifier The problem. Many audiophiles look for Valve and other vintage audio amplifiers in their quest for better sound. There is a technical issue that should be taken into consideration. Most of vintage amplifiers were designed for low output level audio sources like X-tal pick ups or valve radio tuners, sensitivity usually is some 150/200 mVolts, or even 70 mV for, say, excellent old Philips valve amplifiers. This makes difficult and inconvenient to use them with modern sources of 2 Volt RMS standard output like CD or DACs. A vintage amplifier is often get overloaded with nasty distortions because of level mismatch. The higher level signal should be attenuated to match input sensitivity of any particular amplifier. Few manufacturers (say, Kimber) offers attenuating interconnect cables with fixed -11dB, -15dB or -17dB rate, rather expensive, but it is really difficult to find what exact figure fits an amplifier with certain input valve set and in a particular system. If arrenuation is not adjusted accurately sonic result would be either distorted sound or not optimal working point withy extra noise Our solution. We offer here a WBT connector based variable attenuation device to resolve the problem completely. High quality attenuation circuitry mounted inside the best audio grade WBT pass through connector. In picture you may see its internal view with regulation post for just a usual small cross screwdriver The circuitry provides attenuation in between -6dB (just 1/2 of original) to -20dB (1/10 of original) just by turn of the potentiometer. Say, a typical British made vintage amplifier has sensitivity of 200 mV on its Radio or Aux input and would need attenuation of -14dB to match 1V RMS output of a CD player Popular Philips EL64xx series valve amplifier with 120 mV input sensitivity would need -18.4 dB attenuation in the same setup So, nearly any audio source and amplifier can be matched accurately. Important that this tuning is totally safe and can be done in working system. After the adjustment procedure original WBT shell covers the circuit reliably, it remains stable within 1% due to high quality components used - metal film resistors and Kermet potentiometers. How to use it 1. A couple of devices one for each channel should be fitted at input of an amplifier. This allow to use your favourite high quality cables and suppress any interference. We show example of use with Nordost cables, where signal direction shown. The cables are for illustration only and not included to the auction. 2 When a system is connected the correct level an be adjusted with a small cross screwdriver, there is no risk of overload. Important that the maximal undistorted level an be fixed here for each channel and any balance issues an be corrected here 3. If there is fixed certain imbalance in a particular system, originated from listening room geometry, working condition of valves or other reason - this imbalance can be fixed accurately and permanently with this pair of attenuators - obviously any setup can be adjust for equal, correct (and pleasant to hear) sound level in listening point with these attenuators. Usual result of application of the device is better sound performance of an audio system as a whole. Original volume control of amplifier can be used in full scale without distortion or any risk to overload speakers The device was tested by many users and with many types of equipment. Positive result is well confirmed. Attention of International bidders: we will be pleased to ship worldwide. Shipping cost of £14 quoted is initial estimation for EU only. Overseas delivery could cost from £16 (USA, China) to £19 (Australia, South America) We charge an actual minimal for international shipment, please, ask for quotation before bidding to be sure. Pleas note that we ship in 4-5 days after the payment is cleared, please allow some extra time for delivery
Item is fully tested and return is accepted within 2 week after delivery and exclusively in shape as it was shipped, i.e. perfect working condition. In this case 100% of auction price and shipment cost will be refunded. Return of nonworking, damaged or scratched item is not accepted and will be not refunded. Return shipment cost is on Buyer’s side. before bidding to be sure. Unfortunately we can not ship to Vietnam, Russia and Ukraine. |