ramtubes
Responses from ramtubes
| MAC Autoformers? In case you are thinking I made this stuff up, this is really all about history; take a look at this Google search, in this case one for a Fisher A-55:https://www.google.com/search?client=ubuntu&channel=fs&q=fisher+A-55&ie=utf-8&... | |
| MAC Autoformers? BIF,I can match your tubes, may have to sub or sell you a few. Will need to know the plate, screen voltages and cathode current which we do know. Write tubeaudiostore@gmail.com to set it up.I would still like to see a schematic of the amp. Can you... | |
| MAC Autoformers? @almarg I've seen that stated before, but I'm wondering how an amp can be designed with 60 db of feedback. Wouldn't its open loop gain have to be enormous to support a closed loop gain that is reasonable?The open loop gain is enormous and obtai... | |
| MAC Autoformers? BIF,Thanks for the info. Let me clairfy this part which many people make the same mistake. Max power may be compromised at higher impedance, but if I am not pushing the amp, that shouldn't be a problem.I've heard this from ESL owners where the i... | |
| MAC Autoformers? These are examples of speakers that will not play well on low damping amplifiers due to wide impedance swings or very low impedance demanding excessive current. The density of music where dips occurr is important to how much the speaker will overh... | |
| MAC Autoformers? BIF,The tubes will be happiest if you use the tap that is equal to or lower than the lowest impedance of the speaker. So if your lowest is 4 ohms use the 4 ohm tap.Although David Manley (rest his soul) believed that we match the primary of the t... | |
| Autoformers, The Benefits in matching amp to speaker I use a lot of opamps in test equipment I make but not in audio except for a servo. Too may transistors in there.I have a pair of modified Acoustat amps available with an all tube driver stage. No transistors anywhere in the signal path. I am also... | |
| MAC Autoformers? Ralph,Thanks for your answer. I think most of us develop amplifiers in real space verses cyber space. SPICE, by its name, was indeed designed to help people design ICs not tube power amps. The thing that concerns me about 6AS7s, it that they emit ... | |
| Autoformers, The Benefits in matching amp to speaker Should have just bought an automatic car to begin with. (The right amp to do the job)But automatic transmissions still have gears. If there is a right amp for every speaker then does one have to get a new one with every speaker change?I've desig... | |
| Autoformers, The Benefits in matching amp to speaker "An Autoformer or any transformer cannot fix a difficult load and only affects stability in a poorly designed, on the edge amplifier." What I am saying here is that a difficult load stays difficult. The transformer just puts less stress on the ... | |
| Autoformers, The Benefits in matching amp to speaker tomic6011,278 posts09-03-2018 7:46pmRoger - echoing the appreciation for joining this community and hopefully you will see value and continue.i worked atProgressive Audio and we carried the Bev 2, magic when they worked !!!!The model 2 and 2sw w... | |
| Autoformers, The Benefits in matching amp to speaker bifwynne2,044 posts09-03-2018 5:43pmRoger, your comments about speaker crossovers is very interesting. Passive crossovers present another issue: phase coherence problems. I tried to deal with the issue of phase coherence caused by higher orde... | |
| MAC Autoformers? Read this recommended article with caution or not at all. :http://www.normankoren.com/Audio/FeedbackFidelity.html It has many errors and misconceptions. Not a good lesson on feedback. | |
| MAC Autoformers? Since the RM-200 produces about the same power on both taps, what possible reason is there for NOT hooking up a nominal 8 ohm speaker to the 4 ohm tap? Thanks---Eric. This is something that needs clarification. The reason we have taps on tube a... | |
| MAC Autoformers? 10,000 hours is typical- so we warrant the power tubes for a year on this basis, and always have. Ralph, What is your dissipation figure as a percentage of rated? How do you figure in high current peaks when the amp is used at full power? I ... |