Hi David,
He does not do a brisk business. He doesn't come across like an honest person.
-Chris
He does not do a brisk business. He doesn't come across like an honest person.
-Chris
I think most people know when they are being ripped off. I don't understand haw this guy can stay in business. Surely you encountered complaint at your own business even though you were reasonable.
I think the high priced book on Amazon is just a fake listing. A manipulation to get the lower priced book to sell.
Out of print used book prices should be set by demand? Is there that much demand for Bob's book that it should be price at $1000.00 to $10000.00 No one will pay that.
I think the high priced book on Amazon is just a fake listing. A manipulation to get the lower priced book to sell.
Out of print used book prices should be set by demand? Is there that much demand for Bob's book that it should be price at $1000.00 to $10000.00 No one will pay that.
Hi,
I really don't run into that many complaints here. I just try to treat other people as I would like to be treated. That tends to work well.
As for buddy in the book store, I've told him that an offer price has nothing to do with a value. I just had to get a Motorola transistor data book as it was in excellent shape and seemed to have a leather cover. It's very useful for ancient transistor numbers and I've used it often. I didn't like the $25 price he charged, but that was better than the $65 he said it was worth. I'm pretty sure he got it for nothing or $5 ~ $10 tops. There is an air of desperation about him. I don't think he does well, but its what he can do and has a large investment. I should drop in to see if he has anything interesting. You never know ...
-Chris
I really don't run into that many complaints here. I just try to treat other people as I would like to be treated. That tends to work well.
As for buddy in the book store, I've told him that an offer price has nothing to do with a value. I just had to get a Motorola transistor data book as it was in excellent shape and seemed to have a leather cover. It's very useful for ancient transistor numbers and I've used it often. I didn't like the $25 price he charged, but that was better than the $65 he said it was worth. I'm pretty sure he got it for nothing or $5 ~ $10 tops. There is an air of desperation about him. I don't think he does well, but its what he can do and has a large investment. I should drop in to see if he has anything interesting. You never know ...
-Chris
I don't have a real good idea because they don't tell me how many they printed and I don't get a cumulative number in the royalty statement. However, I'm pretty sure that the first print run was between 4000 and 5000. So I'm pretty sure sales exceeded 4000, possibly by a significant amount. This does not include Kindle sales, which I think were only about 10% of all sales.
Cheers,
Bob
Bob when using a jfet long tail input stage how critical is matching of cascode transistors?
Example of a matched pair.
DMMT5551S (Matched Pairs)
| Diodes Incorporated
2% Matched Tolerance, hFE, VCE(SAT), VBE(SAT.
Which parameters are most importance for a cascode transistor?
What are the sensitivities?
Example of a matched pair.
DMMT5551S (Matched Pairs)
| Diodes Incorporated
2% Matched Tolerance, hFE, VCE(SAT), VBE(SAT.
Which parameters are most importance for a cascode transistor?
What are the sensitivities?
Hi David,
I don't think matching of the pair of cascode transistors matters much. I have never bothered to match them or use duals. I think as long as they have a good combination of voltage rating and ft (like the example you showed) they should be fine.
Cheers,
Bob
I don't think matching of the pair of cascode transistors matters much. I have never bothered to match them or use duals. I think as long as they have a good combination of voltage rating and ft (like the example you showed) they should be fine.
Cheers,
Bob
Hi Bob.
I was just wondering if there was going to be an update to your ltspice file containing the components for the simulation section of your 2nd edition?
I was just wondering if there was going to be an update to your ltspice file containing the components for the simulation section of your 2nd edition?
Yes, there will be some updates to the files that are provided on my website. Are those the files you were referring to?
Cheers,
Bob
Cheers,
Bob
Yes, the files on your website used for ltspice simulation. Its fantastic that they will be updated as well when the second edition comes out. Really looking forward to it.
I'm currently hoping for release by the end of September. The book will be about 750 pages and 36 chapters. The manuscript is just about complete.
Cheers,
Bob
Hi Bob and others,
Cheers to Bob on the new release due out shortly. Saving up my $'s
Another topic in audio design that is not well documented imo.
I had a Sansui AU-X901 in for a tune up. I was impressed with this amps ability to control the bass response of a cheap test speaker, an old 6x9 coax in free air. It seemed to be able to get some extra low response out of the free air speaker, unless I am delusional 🙂
Its claim to fame is eliminating the ground noise. It drives the speakers balanced. Sansui called it X-balanced, iirc it was patented.
Any thoughts on Sansui's assumptions that ground noise affects the sound quality in a audio power amplifier and that a balanced speaker drive arrangement can eliminate the effects? Reality or just marketing BS?
Thx
Rick
Cheers to Bob on the new release due out shortly. Saving up my $'s
Another topic in audio design that is not well documented imo.
I had a Sansui AU-X901 in for a tune up. I was impressed with this amps ability to control the bass response of a cheap test speaker, an old 6x9 coax in free air. It seemed to be able to get some extra low response out of the free air speaker, unless I am delusional 🙂
Its claim to fame is eliminating the ground noise. It drives the speakers balanced. Sansui called it X-balanced, iirc it was patented.
Any thoughts on Sansui's assumptions that ground noise affects the sound quality in a audio power amplifier and that a balanced speaker drive arrangement can eliminate the effects? Reality or just marketing BS?
Thx
Rick
I would certainly say that there is more to be said for balanced inputs. On the speaker side it is more difficult to make an argument for balanced drive. Also, on the speaker side there is a lot more snake oil to cloud the issues. There is a technical argument for putting a Zobel network at the speaker end to reduce speaker cable transmission line effects that might affect high frequency stability in some amplifiers.
With regard to how Sansui implemented balanced drive, I would guess that they just used a bridged output amplifier, although that is not the only way to do it. Its difficult to imagine how they got a legitimate patent on that.
Cheers,
Bob
Hi Bob,
I should have clarified that it is not bridged, to drive to the speakers.
It takes a unbalanced line level and in the pre-amp section it makes it balanced to drive the power amp. It also has a balanced input (XLR) for the power amp input. It uses a 6 gang volume control.
I'll post the schematic for reference to take closer look at it if you wish. I trimmed down the service manual to fit the file size requirements.
Rick
I should have clarified that it is not bridged, to drive to the speakers.
It takes a unbalanced line level and in the pre-amp section it makes it balanced to drive the power amp. It also has a balanced input (XLR) for the power amp input. It uses a 6 gang volume control.
I'll post the schematic for reference to take closer look at it if you wish. I trimmed down the service manual to fit the file size requirements.
Rick
Thanks.
But what do you mean by "bridged"?
I see the headphones have 2 transformers. That must be an indication that both speaker outputs are floating -- since headphones usually have a common return and therefore can't be connected to 2 bridged amps for stereo.
Either way, bridged or balanced, the speaker floats and is not part of the ground connection.
In which Sansui stated that this config is better, showing some scope shots, which I believe is "ground noise" in the publications. There is no indication of how, where and on what this measurement was taken.
Is the speaker any better damped/controlled in this configuration? It seemed that way to me.
Glad to see you noticed the transformers for the headphones.
In which Sansui stated that this config is better, showing some scope shots, which I believe is "ground noise" in the publications. There is no indication of how, where and on what this measurement was taken.
Is the speaker any better damped/controlled in this configuration? It seemed that way to me.
Glad to see you noticed the transformers for the headphones.
The Sansui circuit looks very much like what is called a "fully differential amplifier" these days. Which is also similar to Pass' Supersymmetry, but I can't tell if the Sansui is Supersymmetric or not.
Hi Bob, diyAudio site software claims your private message inbox is full. I've tried to send you a regular old email, hope you receive it.