Search results

Curious do you understand what you are quoting? Can you explain how that works?

that is 1/8.

No, it wouldn't make it worse. It will make it better. The primary hum cancelling is in the triode stage, since both plate and cathode injection are coming from the same power supply feed, the less ripple, the less hum. Also, this type of hum cancelling is "static cancelling", so to speak...

There is no such thing as DC feedback in a RC coupled circuit. It is simply a noise injection scheme to cancel the power supply hum at the plate output of VAS.

Back in the days, they probably did not concern too much about exact bias and current balance/tube matching. Changing tubes was more like changing oil back then. But anyone with basic electronic knowledge would know how to measure anode/plate current without tinkering with the circuitry...

It is stereo. The reason for only one woofer is that most of Philco's at the end of tube era were the equivalent of modern day Yorx/Sound Design. They used a tiny SE transformer for each channel and a slightly larger PP transformer to combine bass into one woofer. Cheaper than two normal size SE...

20w is a more realistic number. It is very easy to figure it out. Cathode follower is Class A by defintition. Everyone knows that a 6V6 in class A can only produce 5 watts on a good day. 8 of them is 40 watts, no matter how they are connected, PPP or PSE, and that is in Tetrode mode. In triode...

Don't know what you guys see, but I see a hand crafted amp, with genuine American craftsmanship, of course.

If you like glowing glass, put tubes in microwave, much brighter and more colorful.

But it provides the potential for better vertical alignment of bass and treble, if the cabinet is placed vertically (I have seen people put them sideways like C40).

I know, I have a set just like that.

C43 is a rear-loading bass horn enclosure, the opening is the mouth of the horn. If you put the big Altec horn in the opening, it will block most of the bass horn mouth. Not for a bass horn. The photo OP posted is the correct way of mounting the Altec. If you have a smaller HF horn such as the...

The bottom box and top box are linked through openings to provide slightly more volume for the woofer. The two "windows" on each side of the horn tweeter are actually ports for the woofer.

I have a set of SS-860, bought it purely for novelty. But the sound surprised me, much better than Pioneer CS-88 of the same vintage, without the treble rolloff and has deeper bass. I swept a treble box (which has its own crossover and the horn tweeter and super tweeters) when I first got them...

Thank you Steve O for chipping in. I did not want to get into details because of the way the guy asked the question. LOL. When people come to me for help, they all have audible issues with their amps. One pair of mc30's had low level noise (parasitic oscillation) with electrostatic speakers...

If it is a tank circuit (a LC resonance circuit, for those don't know), it can be damped in different ways. You can damp it with a serial resistor or a parallel resistor. In a grid stopper circuit, the other end of the stopper is connected to the output of previous stage, either plate or...

There is no tank circuit involved in grid stopper. Tube circuit are high impedance circuit. Any wire attached to a tube grid is an antenna and it can capacitively couple to the outputs of later stages. When condition is right, and Murphy's law says it always is, you have oscillation. Because the...

For me, it is CHEAP! I typically pay less than $20 for a console, and maybe in $100 range for a good receiver/integrated like Fisher. I do pay fair market values for desirable pieces, but very few of them are tubed.

Feel free to do so. I have a balance knob, but i don't use it. The way I see it is that if an amp and speakers can't produce balanced sound with full image and stage, something is defective. I always laugh at the reviews that state a piece of equipment suddenly changes the presentation of the...

The power tube bias of MC30 is set up by the 12AX7 cathode follower. In other words, the bias voltage is determined by the voltage on the 12AX7 grid, just a few volts less (more positive), since a cathode follower doesn't exactly follow 100%. You can't simply measure power tube grid to determine...

Can't believe what I read here. A db or two difference between left and right channel will cause sound image to collapse. The resaon OP did not hear any difference is because that feedback is working properly. Feedback resistor ratio sets up the overall gain of the amp. If one power tube is...

Get a Viz Iso-V-AC or something similar if isolation is a concern. It is a combination of an isolation transformer and a variac.

I suppose you can simplify your life by triode strapping the pentode (both suppressor and screen to plate, just like some people do with a EL34) and parallel it with the triode section to form a "giant" triode. With over 3 watts of total dissipation, you can probably get 1w of SE audio out of it...

There is an easy fix, change the name to vidiokarma. LOL.

It is rather simple, transformer size reflects output power rating, X-101-C is rated 27W, 500-c/800-c are 32W, in all cases RMS, based on my old Fisher brochure. All of my stock (with only the bad parts replaced, I am not a shotgun re-cap kind of guy, unless it is a worthless console amp) Fisher...