|  |  |  |  | DIY Audiophile Series, Program #3: Modifying & Upgrading Valve (Tube) Amplifiers This auction is for a brand new, 4 DVD set ( approx. 4 HOURS!), a video do-it-yourself workshop, produced and recorded in Australia by ValveMark founders.
Buy with confidence. So far, the response to this and other programs have been outstandingly positive. Thank you for your kind compliments and continued support!
Some of the comments (read more in our feedback):
...TREMENDOUS...SUPERB, WORK ON THIS DVD !!!! ..MY CONGRATS TO THE CREATORS!!!!
Really a great DVD best for the DIYer Thanks
Very helpful DVD lot of things to learn Great stuff Thanks
Very Clear, precise, step-by-step instructions. Excellent job!
Quick delivery. nicely packaged great info, will buy again …
We have sold our DVDs in Australia, Croatia, Serbia, USA, New Zealand, New Caledonia, Germany, Thailand, Italy, Spain, Brazil, Bulgaria, Canada, Portugal, France, United Kingdom, Ireland, Hong Kong, Greece, Poland, Japan, South Africa, Belgium, South Korea, Austria, Switzerland, Denmark, Chile, Netherlands, Malaysia, Singapore ...
Please browse through our ebay store for more DIY resources, DVD programs, collections of tube circuits and transformer winding diagrams.
How to buy a relatively "cheap" China-made valve (tube) amplifier (but very bad sounding!) and modify it (upgrade it) so it sounds like an audiophile amp five-ten times the price you've paid! Instead of buying an expensive imported "brand name" amps made in USA, UK or elswhere, save thousands of dollars by modifying and fine-tuning a budget Chinese amp and turn it into a sonic bliss!
Any amplifier can be improved, some significantly! Of course, this knowledge will help you improve ANY AMPLIFIER, not just cheap Chinese ones. Many local Perth audiophiles bring their "problematic" amps to Dr Bob for service and improvement. Over the years we have seen American-, British-, Australian-, Italian-, French-made tube amps that left a lot to be desired. Some were badly designed, some badly constructed (kits in particular). Others suffered from both problems. Some were even "famous" brand names, where they sold unsuspecting buyers sizzle instead of steak ... Where is the beef, mate? Some of these unfortunate souls believed in reviews and bought their tube amps unseen and unheard. Big mistake.
PAL (Europe, Australia, NZ,...) or NTSC (USA, Korea, ...) standard, you choose. A set of 4 high-resolution DVD discs, region-free. Total program length: approx. 4 hours!
Save a fortune by buying an inexpensive Chinese-made valve (tube) amplifier and improving its performance! For under US$500 plus transport (often even cheaper than that) and one day of your time, you could end up with an amplifier that sounds as good as audiophile amps in the $4,000 - $6,000 price range. We purchased three different tube amps on e-bay: Music Angel single ended 300B model, Yarland parallel single-ended 2A3 amp and AudioRomy EL34 push-pull amp.
Then, we scrutinised the amps, measured their performance and performed extensive listening tests. We identified many problems and issues (two of the 3 were not even grounded -or earthed -, making them illegal and deadly dangerous) Then we identified all the necessary upgrades and improvements and performed them in front of the camera for you, so you can see how it's done and why!
Learn:
- 8 important steps to take before you decide to purchase a particular tube amp
- How to measure maximum power, maximum undistorted power, damping factor and frequency range of any amplifier
- How to convert an amplifier with self-biasing output stage so it uses fixed bias -this will give you 30%-40% increase in power!
- How to fix certain problems with output transformers (one amp had badly-made audio trafoss, the top frequency limit was only 9.6 kHz, instead of 20-30 kHz!) .
- How to cheaply construct a step-down transformer without spending $100-$150 for a large power transformer (two amps were designed for 220Vac, and would not work properly on Australia's nominal 240 Vac, let alone on the actual measured voltage of 248 Vac!) This is a great trick of ours, just this saving will almost pay for your investment in this program!
- How to convert an ultra-linear or pentode push-pull amplifier into a triode mode (for an incredible improvement in sound quality).
- How to find and remove negative feedback for a vastly more natural and effortless sound!
- How to replace resistors in power suply filtering with chokes (for a 1,500% or 15 times reduced ripple and hum and much better dynamics).
- How to double the power supply filtering (a separate one for each channel) for better channel separation and a quantum leap in sonic performance.
- How to ground (earth) an amplifier (two of our samples were not earthed at all - not just illegal, but downright dangerous)!
- How to determine if the output transformers on your amp are adequate or undersized
- How to replace a tube rectifier with solid state rectifier, for a huge increase in reserve energy of the amplifier's power supply and better dynamics (with SS rectifiers you can use much larger capacitance, hence the increased stored energy). Plus, tube rectifiers don't last long. Since these tubes work full-capacity, all the time, they are the first ones to need replacing.
- A killer fully balanced circuit ("triple differential" topology) that makes a push-pull amplifier with a midrange as good as a single ended amp, but with better & tighter bass, superior top end, more power and more dynamics! Yes, it is possible to get the best of both worlds!
- + much, much more ....
We give you lots of circuit schematics (original and modified options) and sound-improving ideas, we show you tips and tricks for saving your money and your sanity.
Just upgrading the tubes (valves) and some capacitors will NOT get you anywhere, you will just be wasting your money for perhaps a 5% improvement in the sound. If the amplifier design or built is not optimised, tube rolling is inneffective. All three of these amps had more serious issues which had to be rectified if any significant sonic improvement was to be achieved.
Apart from all the action filmed on top-resolution (highest quality) DVDs, this program comes with a bonus photo album with 62 full colour photos! Schematics, close-up shots of important details, the photos of the flip-charts used in the program. This DVD workshop is a "must have" for all serious audiophiles and DIY constructors and tweakers who want to improve their existing amplifier (you can apply these principles to improving any amplifier!)
The information revealed in this video program is not available in a visual format - finally you can see how it's done and hear the commentary while each operation is being performed. Reading about something is one thing, and seeing an expert do it in front of you (and explain how and why) is something completely different!
Thank you for your interest. I wish you every success with your DIY project and your tweaking efforts. Please let us know of your achievements and/or any difficulties your faced on your quest for good sound. If either Igor or myself can help you, just e-mail us! Dr Bob
REGARDING CHEPSKATES AND LOW-BALLERS:
I have been receiving low-ball offers on some of our DVD programs (those with a "Best offer" option), $12, $40 and so on. These are insulting. Try making such offers to a plummer, car dealer or your doctor or dentist! Some people even commented on internet forums that $100+ for 3 or 4 DVDs is too expensive. Maybe they are too cheap ...
Here is how I see it:
1. These DVD programs are the only ones of this kind in the world, unique. Therefore no price is too high, since you have no other option - you cannot buy a competing from anybody else. I think that AU$109 or AU$119 per set is actually too cheap. That is the cost of a mediocre 3-course dinner and drinks for one in an ordinary restaurant in Australia!
2. You are not getting just a DVD set but a full color-laser printed book to go with it, and with some programs, a colour laminated sign.
3. Each of our DVD programs took months to script, film and edit. Booklets took weeks to design, edit, print and bind. The investment in filming equipment only was more than $3,000, not counting computers, professional video editing software, multiple disk burners, colour laser and inkjet printers and so on. The there is a high investment in amplifiers fetured, test & measuring equipment, parts and components and the like. All those expenses have to be costed and recouped from the modest price of our DVD workshops.
4. Ultimately, you are not buying DVDs, you are buying knowledge! This knowledge comes from more than 80 years of combined professional experience in physics, tube and solid-state electronics, audio manufacturing & retailing, and teaching and training business (Dr Bob since 1950's and Igor since 1980's).
5. This is how I make my living - selling these DVD programs is my only source of income. Igor and Bob provide their assistance and their valuable time for free. I cannot wish for a better husband or nicer father-in-law.
6. Although ongoing technical support and advice is, stricctly speaking, NOT included in the cost of a program, Igor and Bob are happy to answer any reasonable question you may have, free of charge. They cannot spend two hours guiding you through your DIY project for free, but a question or two that take 10-15 minutes to answer via email, we are happy to oblige. That is additional value you get for the modest price of our DVD programs.
7. Most importantly, I have never had one unhappy or unsatisfied buyer, someone who wanted to return a DVD program he or she bought. That tells you something. We ship on the same day of the payment and you get your stuff within 3 days in Australia and within 8-14 days world-wide. Although airmail (untraceable) postage is at buyer's risk, in a few very rare cases where the package does not arrive, we replace it at our expense - we don't want undeserved negative feedback, we want you to be happy! In other words, I try to make your experience with us a real pleasure.
So, if you still think our DVD prorgams are not the best value-for-money around, feel free to spend hundreds of hours searching the web for this information (most of it you'll never find since it isn't there), and then a few more hundreds of hours trying to make sense out if it all, reconcilling often contradictory claims and false information from amateurs, Good luck!
Thank you for your trust and your purchases! Best wishes, Elena |
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