3dzapper Posted April 3, 2005 Author Share Posted April 3, 2005 Rock'n amps!! I like that idea! Quote Link to comment Share on other sites More sharing options...
3dzapper Posted April 4, 2005 Author Share Posted April 4, 2005 Just got off the phone with the seller, Guitarampski. I learned a bit of history on these. They came from a Baldwin Model 12 organ at Purdue University. The manuals had like 36 of these. The output trannys are heavier and larger than Mark IIIs and the wattage is higher. He thinks in the 85 watt range(?). Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted April 6, 2005 Share Posted April 6, 2005 Cathodes drive the output tubes. What would be the name of that driver circuit topology? 'Cathode Follower,' which can provide good (low) output impedance matching with the next stage. Cathode followers are sometimes used as a 'buffer' between stages for impedance matching purposes only, since they don't offer voltage gain. SRPP is another possibility. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted April 6, 2005 Share Posted April 6, 2005 PS: Rick those amps look like they may be really, really good. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted April 6, 2005 Share Posted April 6, 2005 Hmmmm.... This makes me think about something: I've seen cathode followers or a feedback incorporating variation on this called the White cathode follower used as low output impedance buffers in 'passive' preamplifiers. With passives, there is often a problem of high output impedances (resulting from the value of the potentiometer being used)trying to drive the high capacitances of long runs of interconnect, and the use of a zero-gain cathode follower can offset the capacitance issues by providing very low output impedances -- very much like a transformer-coupled passive switch box/attenuation device (aka 'passive preamp'). while cathode follower driver and even output stages (a few examples of which I have seen)present usefully low output impedances, they do have some other 'issues.' In any event, I really look forward to hearing what you have to say about the Baldwin Monoblocks. I enjoyed Craigs Baldwin very much, and a monoblock pair could have certain advantages. Neat! Erik Quote Link to comment Share on other sites More sharing options...
mike stehr Posted April 6, 2005 Share Posted April 6, 2005 Thanks Erik, makes sense.....Voltage stage, with the inverter as a cathode follower.... The 12BH7 has a Rp of around 5500 ohms, that doesn't seem too terribly high? That's about the right Rp for my Electra-Print L3503 line out OPT's. Hmmm..... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.