Ar9Jim

The Phase 700. It made more power than anyone else and it put me on the map. Before that it was Bob who? Least favorite- I love them all like children.

A) Bob - I think it has to do with people liking larger transformers. With the inverting design you can get the same power from a transformer about 1/2 the size, saving weight and making the products more affordable. It's been successful for me in the market.

A) Bob- For myself I just like the tubes. Listening to music at night with the tubes glowing is just special.

Bob, In the Crimson 275 why did you use your Edcor EM0946 output transformers that you had designed years earlier. They are labeled only 15 watts. Why were those chosen? The owners adore the Crimson 275s and no one can deny that they sound great. How and why are they built so light? What were the design goals?

It's a subjective question. You may be happy with solid state Carver gear because it has a tube amp like transfer function by design. Being happy with it, you have no reason to buy a tube amp. Has Bob improved sonic performance in the last 25 or 30 years? Of course he has, but the solid state will still measure better than a tube amp, so objectively there is no reason to buy a tube amp. You have to compare Bobs tube amps for yourself to determine the sonic value to you. That's why we have the Carver Amp Challenge. We don't expect anyone to take our word for it. We don't deal in snake oil at one extreme in the hobby or chasing the best numbers at the expense of sound quality priorities, to satisfy the best measurements sounds best believers. If best measurements are the goal, solid state is the way to go. People have to experience audio. Then the choice is clear. It just happens to land in our favor 98% of the time. I'll ask Bob what he thinks, but this reflects our mission statement. Great question.

I'll be talking to Bob in the next couple days. I'm writing down questions. Feel free to ask your question of the week about anything, past, present or future. Controversial topics are encouraged. Crimson 275 questions are welcome. Ram 285 questions are welcome. Questions of science vs audio beliefs, or any topic you would like a short, straight, honest answer about, ask here. Don't be shy! Enjoy! UPDATE: Now question of the week is a regular weekly event.. Post questions before Thursday and have an answer on the weekend.. Our hobby is polarized and being taken advantage of with beliefs at both extremes at the hobbies expense. Bob Carver has been a maverick in this industry for many decades by simple telling the truth as filtered through his physics and mathematics education, combined with decades of study and experimentation. Bob is great at explaining and is a wonderful teacher.

Ram 285 transformers from another view. For scale, the bottom portion of the chassis is 3-1/2 inches high and 17" wide. The transformer section is 5-1/2" high. The copper color shows accurately in this picture. Same amp in the previous picture but the previous picture looks too orange. Customers are really liking the copper. Note the CNC machining on the top cover. Note the copper chassis is chamfered where the wire pass though. All of the exposed outside corners are radiused. The copper anodized top plate is almost 1/4 in. thick (6mm) 6061 alum..

Customer in California received his RAM 285. Thank you, Watt. Enjoy your trip to Bangkok. Dear Jim and Lerma: I got the Ram 285 tube amp yesterday. I hook them up and enjoy playing for couple hours. The unit is very pretty and very heavy. Thank you for beautiful product. Thank you, Watt

Here is a quick pic of the RAM 285 transformers. Some will be added to the site. More nudes coming today. These 100watt Hammond transformers are matched pairs and the frequency response stays flat below 18Hz beyond full rated power.. The chassis is a full 17 inches wide. The amps weighs 56lbs.

The color of these pictures are close. We updated the site with better pictures and closer viewpoints. In sleep mode all power supplies are off. In stand-by, the low voltage supply is on and the tubes glow and stay warm. On- Activates the high voltage supply together with low voltage supply. Light- Simply activates the meter light while under power

RAM 285 after burn in and line test. Final step is arriving here for listening test. The amps stay on their cart through the process. Listening test are normally performed on Tuesdays and Thursdays. Demo's are also available on Tuesdays and Thursdays in Rockford, IL. by appointment. You are welcome to participate in listening test of the RAM 285s and Black Magic products before they ship out.

Yeah, that's a good color match. It's difficult to get right in the pictures. This is a good photo. The luster in the light is nice!

Q. What is the finish used on the RAM 285? Is it painted? Will the copper tarnish? A. Great question. The entire chassis is CNC machined from thick 6061 aluminum. The copper cover portion is 6mm thick. The black and copper colors are anodize finishes, not paint. Anodize provides a nice even, sealed, durable finish as used in high end aluminum automotive and aircraft parts (commonly blue or gold in color) we use copper and black. https://www.anodizing.org/page/what-is-anodizing

RAM 285s moving along. In person the copper finish matches the color of fresh copper wire or a new copper penny. Customers are calling it "captivating", "stunning", "beautiful", "the anodize is nicer than paint". We are very happy with the initial feedback about sound, fit and finish.

iamjohngalt11 Nov 3:32 PM @Ar9Jim I just got a TFM-42 restored by Greg. I've run it on my 2.5R Maggies (driven with 10 Octave LP1) and at moderate loudness on Jazz vocals the LED meters are jumping up to full height with regularity. I tested the same amp on Bill's Altec speakers and the LED's don't move off the low one at all. Full size Maggies really need some power. iamjohngalt11 Nov 3:35 PM Didn't you demo those MGIIIa's with a Carver 275 regularly in your sales listening room? Hello JG.. Yes, have used 275s on the Maggies alot. Also with the ALS line source and those are not an easy load running about 50 drivers in one pair of speakers. Maggies really like the high voltage side of the V x A = W math. Easiest analogy is water. Physics are fundamental. The garden hose will flow current well, but you can stop it with your thumb. Now crank it up to 1000psi (pressure / electromotive force in electrons) of a pressure washer. Now you do not want to put your thumb on it. "Current needs to be enough" Bob Carver. If your design priority is testing well with resistive load drain test, then you will be distracted from the application and that's ok. It's a good way to get good reviews, but of limited value to the customer looking for a powerful, musical and accurate reproduction of music. People are so smart but yet the basic differences between reactive loads and resistors are beyond understanding. Voltage swing moves loudspeakers. Car battery has huge current and will smoke low resistance loads right. But you can put your hands on the post and nothing happens. That's good for low impedance drain test. But how does the power supply respond with the impedance (AC resistance) goes up? "My design increases voltage with increased impedance." Bob Carver. Can see it in the designs. 685, 740, 800. At 800v custom capacitors get expensive. At the 285 voltage the 1000v B+ fuses for a littelfuse can cost $10 each. They have some for $5 Fun stuff. One of the 285 customers owns a company that rents sounds systems for concerts to bands. He is in the Hollywood area. I was telling him how the 285 was built heavy and makes excess current. He says "I don't care about that, how does it punch?" This is in his home stereo, but his mindset is dynamics. Or voltage swing in other words. So the RAM 285 is built for both high voltage and high current at a shipping weight of 60lbs and Bob took the voltage even higher. It's awesome. At full power output it doesn't start to roll off in frequency response until below 18Hz.. https://www.ap.com/technical-library/measuring-power-amplifiers-with-reactive-loads/

The RAM 285 is a great testing amp for comparison with tube amps. It meets it's specs and sounds wonderful. The folks at ASR are playing a numbers belief game that what measures best, should technically sound the best. This incentivizes a numbers race well past audibility, over sound quality and a host of other priorities considered in creating a musically enjoyable design with real customer value for it's intended application. Naturally, an ASR review would not recommend a RAM 285 because solid state devices can measure far better than vacuum tubes by orders of magnitude. Solid State is much lower cost to build and will measure better than vacuum tube amplifiers, unless greater complexity than is necessary for audio is added to the tube amp design, increasing the build cost even higher needlessly. Some will always purchase audio products considering the best measurements as the true measure of sonic value, and that's great. There's certainly nothing wrong with that viewpoint. A tube amp at 1Khz with .2 %THD+N vs a solid state at .00002% and the choice seems perfectly clear and made really easy for some. These measurements are really simple to comprehend and to judge products by. It's scientific. It's good. These consumers would never purchase a tube amp of any brand and they shouldn't without hearing them first. This is a solid state type customer, not a tube amp customer, by nature. At the opposite end of the spectrum from ASR, you have people describing the subjective qualities of listening to multi-thousand dollar power cords. What is the customer supposed to believe in this day and age, with the hobby so polarized into these 2 camps? This is why we have the Carver Amp Challenge. Our customers do not need to rely on subjective reviews or best measurement reviews at either of the extremes in the hobby. Hearing our products in their system compared to others, answers all their questions and sends many much more expensive solid state and tube designs back for refunds.

Q: Bob, How can the tubes run cooler and last for decades when most manufacturers tubes run very hot and recommend changing the tubes in their amps in 3 years. A: That is a very good question! The answer is the DC Restorer. Here’s how. Most amps idle the output tubes at an average of 32 watts or so. Now the DC Restorer allows the tubes to idle at about 9.75 watts. Since tube longevity is roughly proportional to the plate dissipation raised to the 2.3 power, we have 32 divided by 9.75 raised to the power of 2.3 = 15.4. Finally, 15.4 X 3 years = 46 years. Tube amplifiers are normally biased-up like they are running flat out, even at idle, to keep distortion low. The DC Restorer is a dynamic bias supply. The lower idle current allows for cooler running tube temperatures and much longer tube life while maintaining low distortion. It's a circuit that was used in tube type color TVs that were very sensitive to DC voltage sag. I adapted a version for audio and It has really been a great circuit.

RAM 285 preorders are being delivered to customers and will be 100% filled next week 11-17-23 We are working hard to get the RAM 285s on the shelves for fast, world class delivery before the end of Nov.. Order now.

No problem. Please send to: Bob Carver 4563 Hydraulic Rd Rockford, IL, 61109

Carl, Current products (tube amps) are serviced in Rockford, IL.. Vintage (solid state in our case) are service at Nelion and Hi Tech. Bob Carver products since about 1970 are still being serviced and serving happy customers today. I'll make this clearer on the website. Thanks.

Here is a picture of a recent production board. The AC filament wires were move to the top side of the board. The missing Zobel network prevents oscillation if the amp is powered up without a speaker load connected. It's important not to power it up as Wayne said. Any parts the amp needs are available. We have one here in Rockford with a bad power transformer. The owners son was running multiple 4 ohm speakers on each channel and the trans eventually failed shorted. With the fuse covers missing and the smoked resistors, I'm guessing the power trans is bad, worst case. If Greg is isn't interested or if the wait is too long, you can send it to Bob Carver in Rockford for repair. Jim 815 985 3557

Welcome back Carl!

Welcome back Steven!

Had a meeting with Bob today and went through the questions list. Question- Bob, The topic of power conditioners came up and I mentioned all Bob Carver amps should be plugged directly to the wall. One customer mentioned his concern for having unstable rural power that can blink and act odd. He is asking if protection is needed to protect Carver amps especially his SS900s. Bob - Not at all. The power supplies can handle all of that. Plug them directly to the wall and enjoy!

Small portion of the RAM 285 2 sided, multi layer, main board. These 800v film caps were custom made for this voltage. These 1% low noise Dale resistors contribute to the SNR of 100-102. The SNR might be even better. The RAM285 is checking at the limits of this analyzer, reading the same as connecting a 1m cable alone. With the inputs shorted, you have to almost touch your ear to the dome tweeter to hear anything at all. Reference Amplifier. https://www.vishay.com/docs/31018/cmfind.pdf