lynn_olson
Responses from lynn_olson
| Spatial Audio Raven Preamp Any info on your power amps? Input sensitivity (volts RMS to clip the amp) and input impedance should tell the tale. Transistor amps (with feedback) are typically 1~2 volts to clip amp, and input impedance is typically 10K to 22K. The Bruno Putz... | |
| DarTzeel’s new direction Using medium impedance (50 to 300 ohms) for line-level interconnects is a good idea, although not suitable for modern studio practice. And medium impedance for speaker outputs (1 to 2 ohms) is going to depend on the complexity of the speaker cross... | |
| DarTzeel’s new direction The oligarch market is probably saturated. This isn’t meant as a joke; with the Russians shut out of the West, there are fewer oligarchs around, so the market itself has fewer buyers today than five years ago. And it can’t be all that big ... mayb... | |
| Spatial Audio Raven Preamp We take for granted the very low prices of modern solid-state electronics. For a little perspective, look at the price of a RCA 21" color TV or Fisher FM/AM receiver in 1964. The cheapest color set was $500, and the receiver was $350. Wow, what a ... | |
| Spatial Audio Raven Preamp For better or worse, the Raven and Blackbird have high parts costs. Instead of a 1/4" thick sculpted aluminum faceplate (marketing!), we put the money into custom parts that are in the audio path. Pro-quality connectors, high-purity wire, custom t... | |
| 300b lovers The cathode circuit is quite sensitive to (subjective) parts coloration ... not surprising, because both grid and cathode are the two input nodes for vacuum tubes. The difference is the grid circuit has very low current flow (but not zero) while t... | |
| 300b lovers The takeaway is that is impossible to "overdrive" the 300B. By contrast, a charmer like an EL84 can be driven with a whisper ... even a 12AX7 biased at 1 mA will sound good as a driver (which doesn’t work with any other power tube). A classic Mull... | |
| 300b lovers I left the driver tuning up to Don Sachs, who’s been building PP pentode amps for decades ... and started out by restoring Citation I and II’s, which are notorious as the most complex amps and preamps of the Golden Age. By contrast, the Marantz am... | |
| Spatial Audio Raven Preamp fthomsom251, you bring up a good point. When Don and I ditched the coupling capacitors, that pretty much got rid of the most obvious way of "tuning" the Raven. You see, nearly all coupling caps have a sound, one way or another. Get rid of them, th... | |
| Is Mark Levinson still considered up there with the best of the best? The power relationship between designer, corporate CEO, and the marketing department are different for every company. Quite a few well-known high-end companies (not going to name names here) are little more than marketing departments, hiring desig... | |
| Is Mark Levinson still considered up there with the best of the best? What matters is the designer, not the manufacturer or the promoter/salesman/marketer. The designer is responsible for the sound ... the marketer just sells it. If a manufacturer changes their house sound, that means the design staff has changed or... | |
| Spatial Audio Raven Preamp Kind of expected because: 1) the specialized damper diode rectifiers have very soft switching compared to solid-state diodes, thus much less 50/60 Hz switching noise radiated into the rest of the circuit and out the AC power cord 2) the regulate... | |
| DC Offset Issue in Don Sachs Preamp Actually, posting these little "how-tos" on the forum is good for me, since the content can be added to the product manuals. I’m the one that writes them for Spatial. Plenty of experience writing these things ... nine years at Tektronix in Oregon... | |
| DC Offset Issue in Don Sachs Preamp The final stage of the preamp is a cathode follower with an active pull-down, which is cap-coupled to the RCA output. The output is shunted by a large-value resistor to discharge the output cap. Don’t remember if there is a muting relay to mute th... | |
| DC Offset Issue in Don Sachs Preamp Don is still with us, contact him by email. My guess is the load resistor on the output of the cap has gone open, but I wouldn’t expect both channels to do that at the same time. Maybe something has gone wrong with the regulator. It would help to ... |