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Found 5 results

  1. This preamp needs no full introduction as it is one of the best tube dht preamps you can buy for its money so I’ll jump straight into the specifics. I’m the 3rd owner, the unit has had some TLC done to it. All resistors changed on the CCS boards, HT PSU etc where necessary. The cheap crappy CCS trimpots have been changed with US made Precision 10 turn 1k pots so forget about jumpy measurements with the default pots which are inaccurate. All electrolytic capacitors bypassed with poly and metalised films where necessary. Some boards cleaned up a bit but I’ll still be adding some final touches to it today (mainly just dressing it up and cleaning the internals). I have 3 Tram 2 preamps and will also be listing another unit later on. Lovely dht sound. Dead quiet. The Tram 2 comes with a pair Of Sylvania 45’s, 2 x 5U4G rectifiers and 2 x 6AS7G tubes. Also comes with original remote which I never used it may need to be programmed. All tubes tested strong to NOS readings on my AVO vcm mk2.
  2. Item: see above Location: Western Suburbs Melbourne Price: $1600 Item Condition: I consider it fair to good, some nicks and scuffs here and there, expect wear and tear. Reason for selling: surplus, need the funds for new house. Payment Method: Pickup - Cash, Paypal Extra Info: This preamp needs no full introduction as it is one of the best tube dht preamps you can buy for its money so I’ll jump straight into the specifics. I’m the 3rd owner, the unit has had some TLC done to it. All resistors changed on the CCS boards, HT PSU etc where necessary. The cheap crappy CCS trimpots have been changed with US made Precision 10 turn 1k pots so forget about jumpy measurements with the default pots which are inaccurate. All electrolytic capacitors bypassed with poly and metalised films where necessary. Some boards cleaned up a bit but I’ll still be adding some final touches to it today (mainly just dressing it up and cleaning the internals). I have 3 Tram 2 preamps and will also be listing another unit later on. Lovely dht sound. Dead quiet. The Tram 2 comes with a pair Of Sylvania 45’s, 2 x 5U4G rectifiers and 2 x 6AS7G tubes. Also comes with original remote which I never used it may need to be programmed. All tubes tested strong to NOS readings on my AVO vcm mk2.
  3. Item: Custom Built 01A Valve Based Preamplifier Location: Tauranga NZ Price: $1200 AUD $1000 Item Condition: Very Good ( I say this only as it's handmade and built to sound good ) Reason for selling: Down sizing my system Payment Method: Paypal (+3.5%) or deposit into my brothers Australian account to avoid fees Extra Info: Purchased approx 12 months ago and hasn't been used for the last 6 months. I was going to keep this but now I don't have a vinyl rig, so, I need to free up some funds for a cheaper digital system. Sylvania rectifier, pair of RCA UX201A and 3 Ceco 201A included 110v so a step down transformer is also included. At this price it's a real bargain and a pain free way to try a DHT preamp if you've been wondering like I was. Below is the description from the builder. Hello, The preamp is one stage, common cathode(filament in this case) with inductance simulated load. The input is direct coupled through Alps potentiometers. The output is capacitor coupled, using a 2.2uF Ampohm PIO. The bias of the tubes is quasi fixed using a filament bias scenario, where the filament current ( about 230mA-starved mode for lowering the microphony) is supplied through filament and a power resistor to ground. This resistor has a 30ohms (low) value and there is no need for filament decoupling. This way one of the capacitor in signal path was avoided. I used the excellent Coleman filament regulator for a hum free preamp. The power supply is using three transformers ( one for main HT and two for filaments). The high tension (HT) is provided by tube rectification ( 6BY5GA) in quasi choke input mode,CLCRC filtering with a 0.68uF-30H/40mA choke followed by twice of 10uF Obbligato parallel with 47uF Mundorf Mlytic, followed by a solid state shunt regulator. The power consumption is about 40W. The audio tubes are 01As and are available as NOS or used. These tubes are from 1920-1930s and have special sound probably related to the fact that their filaments are Thoriated Tungsten. Their sockets are mounted using neoprene dampers to reduce the impact of vibrations ( whoever is familiar with direct heated tubes, knows that they are microphonic..and 01A is not an exception). The sockets are very loose so the they dampen any vibration. the 01As are to to be remove or installed by gently tilting left and right with just enough pressure. Depending on the selected tube used, the THD that is mostly 2nd harmonic could be as low as 0.03% at max output of about 16V. Frequency response is excellent and was measured as 12-24kHz @-0.5dB for 8Vrms output. This preamp's output impedance was measured by comparing the voltage drop from a 500k/300pF load to a 10K/300pF load and the result was around 470ohms. This preamp provides a unique sound of the 01A tube...the magic of DHT and Thoriated Tungsten filament. If you have a system that needs a DHT triode touch, then this could be a great option. One of the most popular upgrades is to replace the actual anode load with a line output transformer ( LL2745/PP(good to 5mA in single ended configuration) is recommended. I will gladly help with technical advice. The actual gain of the preamp is about 18dB ( or x8). With LL2745 in 5.6:1 configuration the gain will be reduced to about 3dB (or x1.42). There is also another option using a parafeed setup. This way one can use a non-gapped transformer with better frequency response.
  4. What's your favourite 2A3? Pictures and explanation appreciated please. Ive only got NOS RCA VT-95 so far and to me they sound dynamic, quiet and full bodied in the Tram2
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