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Where can I buy/see/read info on Dennis Had's amplifiers?Thanks!
@Canada RobI had bad experiences with solid state so far. But I will have a look. Thanks!@BeatlebumThanks for the offer! Does the Inspire IFA-1accept EL34 or 84 tubes too? How can I get more information about Dennis Had amps? Can barely find anything about them. Looks like a secret club or something..!
.................Same thing with the Line Magnetic 216ia (KT88, UL push-pull).
If I understand correctly (I am not a technical guy at all and I am really new to tube amplifiers), the Inspire IFA-1 is a power amplifier that must be used with a preamp/line stage like the LP-27a? Or is it an integrated? Can it be used alone? Is the Inspire IFA-1 a SEP or a PSE?
The IFA-1 precedes the Firebottle HO and appears to be of identical electrical layout, just physically different. My KT88HO has the same 6DJ8>KT88 layout as an IFA-1. I would imagine them to both behave similarly. Both lack an input tube and have only a single stage driver tube (double triode split between two channels) and a single output tube. While they can be driven directly from a source, they do better with a preamp unless your source is running a least 3 or 4 volts.I've said that the Inspire amps can best be viewed as half of an integrated amp and need a gain stage to be at their best. Other amps also "need' a preamp as well, while others have a low input sensitivity and high enough gain to stand on their own. I have a SE 421A amp that has only two stages: 6SL7 > 421A. But the 6SL7 is a high gain tube and the 421A is easy to drive. It gets its full 4wpc output with less than 0.5 volts at the input. If I added more inputs and a selector switch it would be a valid integrated amp.
Yup, 6SN7 is only enough for ~15 dB gain in that scenario, more or less depending on the power tube but it's much less than typical. 6SL7 gives more typical gain but isn't suitable for driving most power tubes. If the SL7 is followed by a SN7 White cathode follower or Broski's Aikido cathode follower then you have a fairly ideal driver circuit imo, but that's one more stage... Also, not super ideal if it doesn't have it's own power supply, which is where a separate preamp is going to be more ideal... My setup runs the SL7 > SN7 CF output as a voltage amp in it's own chassis/power supply then the power tube in it's own chassis/PS, so it's basically a voltage amp followed by a power buffer. After years of experimentation I've found this works really well. I've tested SS amps that are more slow/tubey sounding vs my setup...