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Item: A Pair of Telefunken 12AX-7 Smooth Plate (selected tube if possible)
Price Range: $250 - $300
Item Condition: New or Used
Extra Info: Looking for a pair of TFK 12AX7 Smooth plates, preferably selected tubes.
Do let me know if anybody is willing to part with theirs.
Please don't forget to report your post as FOUND when possible. (You can now delete this text).
Item Condition: 9/10 Shipping Options: Pickup available but audition is not available. Suburb or Town: Highett State: VIC Payment Method: Bank transer Or paypal Reason for selling: Not Needed Further information:
was just serviced By melody and tubes only have 8 hours of play on them.
i have the box it came in Aswell.
pick up only due to the amp weighing 35KGS
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Hi all, I am looking for some advice as to where best to source three (including a matched pair) of 12ax7 valves for my minimax phono preamp. It also takes a 6x4 rectifier but not sure if I need /want to replace this.
I have the stock valves that came with the amp from Eastern Electric and I’ve had it for 10 years now, just upgrading my main amp and want to try something better that will do the rest of my system justice. (Michell Gorbe/SME m2/9 / Lyra/ Sugden Masterclass/ Goodman Magnum K’s.)
I’m bit wary of eBay so would really appreciate some guidance for reputable resellers.
I’ve read a fair bit about different types, my budget is a few hundred dollars.
Thanks in advance !
Item Condition: Very Good Shipping Options: Shipping is available at agreed cost. Suburb or Town: Melbourne State: Victoria Payment Method: EFT Reason for selling: NLR Further information:
Selling my Bob Carver 350 Mono Amplifier, the amplifier was custom made in 240 Volts specifically so there is no need for a step down transformer. The condition is excellent hardly used, build quality is super,and each amplifier is individually handcrafted in the USA by "Tubular" Joe Bonin. Both amplifiers are finished in a lovely crimson red colour which looks absolutely superb. Due to inherent design of the amplifier the Power Tubes which are the KT120 have a increased lifespan and run much cooler.
In terms of power, the amplifiers are rated at 350 into 8 and 400 into 4 more than enough power to drive the most difficult of speakers. I have all the original packaging so shipping should not be a problem.
If you have any questions or would like further information please do not hesitate to contact me.
Price is Negotiable.
If you are advertising multiple items, you must post one bulk price only, or post seperate ads for each item If you include any reference to pricing whatsoever in this section (excluding RRP), your ad will not be approved If you don't include photographs of the actual item being sold, your ad will not be approved
I am not an expert on tube amp like many on this forum however writing this blog to help those who are thinking of buying Willsenton R8 or those who owns it and want to know bit more about it. I am not good with ears as Audiophile guys but can provide some technical insight.
Initially I was thinking of building my own tube amp as I am a keen DIYer but then looked on the net and saw hype about R8. Pulled the trigger in the hope that it is Point to Point wired amp so if not good, I will enjoy modifying it rather than building from the scratch.
Received my amp 5 days ago and first thing I did is that I opened up back cover before even trying it out. I was curious to know the quality of soldering, and the internal voltage switch is correctly set to run on 240V. To my surprise, it was great. I did not have to re-solder any point, all the components used are of good quality, relays and electrolyte caps are of reputed Japanese brands. Coupling caps and Grid bypass cap in driver stage are own ‘Willsenton’ branded but looks good (and looking at the way it sounds, I don’t think there is a need of replacing those with better branded caps or PIO caps). All the components and cables are laid out properly and tied together. The only flaw I found was that the outside sticker displays 240V but the inside voltage selector switch shows 230V. Also, I could not see Capacitor discharge resistor on main filter caps.
After satisfied with the build quality, I connected the amp to my system and wow… it sounds amazing and better than my other tube and SS amps. It is dead quiet when no signal and the sound is just clean, open and excellent coverage at both bottom and upper end. While it was sounding great, I found that the outer casing of power transformer was warming up a bit. The casing felt like a thick sheet of metal hence was bit concerned about the actual temperature of the transformer itself. Also, the bias was bit on the higher side when I checked first time which created the doubt that they have actually used 230V trannie and just put the sticker of 240V.
However, with these concerns in the mind, I decided to partially tear down the amp over the weekend to check the Power transformer rating, measure all voltages, trace down Schematic and install a discharge resistor on the filter cap. Supplier sent me the Schematic but it was too basic and wanted to confirm that it is accurate.
Below are my findings.
About 30% of resistor values in amp are different to actual schematic. The capacitance multiplier circuit is also different and there are some typo errors as well. I ended up drawing my own. Transformers are potted in the casing (which is a great thing) hence did not remove those as it would require de-soldering of too many connections. However, when measured the heater voltage, it was precisely 6.33V at my home supply voltage of 245V which indicates that it is a 240V transformer and switch labelling is not correct. The potting of transformer also explains that the heat on the casing is a conduction from transformer and not the radiation (which would be in case of hollow casing), so nothing to worry about it. Potted transformers also explain why this unit is so heavy and outer casings feel like made of a thick metal sheet. KT88/EL34 switch changes the negative Grid voltage to power tubes and calibrates front Bias meter. I was expecting this switch to change the B+ voltage for different tubes but that’s ok, you can’t get everything at such a low price. B+ measures about 440V. This is optimum for EL34 but KT88 would have performed better with bit more voltage of about 500V or more. The soft start delay circuit does not delay B+ supply voltage to tubes but rather mutes input signals for 30 seconds after turning it on. At least something is better than nothing. I am not 100% sure about the Pre-IN input but I think it is not directly fed to driver stage bypassing pre-amp section. It still goes through pre-amp and volume control is bypassed to mimic the Power amp only condition. I do not use this input so didn’t bother going into further details. The designer has taken great efforts to minimise noise in the amp by adopting Capacitance Multiplier using tubes to remove ripples from the supply voltage before it is fed to Pre-amp tubes. An elevated heater supply using virtual ground is also used to heat preamp tubes to prevent humming. 6SL7 are great tubes for audio application but at the same time they are high gain tubes and hence prone to noise and humming. With implementation of these 2 measures, amp is extremely quiet and noise free. The elevated heater supply circuit also works as a capacitor discharge and no need to add additional resistor on the cap. I measured that after turning off the amp, there is hardly any voltage on power caps within 3 seconds, so it is very safe from that point of view. One drawback of this amp is that it uses digital circuit for input and TR/UL selection but there is no memory function. If you are using CD as an input source and TR mode, then you do not have to do anything. For anything else, each time you turn on amp, you will have to select the source and the mode. A simple rotary selector switch would have been a better option here.
In conclusion, this is a great amp as a value for money. I am not an audiophile and do not own too many amps so I would leave those reviews and comparison for Youtubers but from the technical point of view, you will not get anything better sounding and better-quality product in this price. Looking at how it performs in bottom and top end, I am sure that the output transformers are also of great quality which is heart and soul of any tube amplifier.
I don’t’ think spending thousands of $ and buying Prima Luna or something like that will give any kind of added benefits. Just roll few tubes on this and it will shine like those branded amps costing multi-folds. This is my personal opinion considering my own circumstances and others may have different opinion and I respect that as well.
As a summary, it is nicely designed for flexibility of tube rolling, manufactured with quality components, built with care and professionalism, very reasonably priced and most important, it also sounds great.
Waiting for lock down in Melbourne to open so that I can try some tube rolling :-).