and you would still have been wrong from the point I highlight in red.
Even bitd there were options that would have performed significantly better as a CF intended to drive into a load. 12au7/ecc82 being one of them which was neither exotic nor expensive then or now.
You forgot the lowly 12AY7 tube. (45 gain vs X7's 100)
I've used it in an amplifier build, (concertina duty) driving some 7189A's/EL84's with great results.
The "built up" hero's of audio, or should I say "reputations", are mostly human-cultivated, word-of-mouth entities.
Just like anything else on the planet, including gold, silver, diamonds....Mercedes Benz, Audi.... Apple, Samsung....... you get the idea?
It's marketing, plain and simple, consumerism at its finest.
And once something is "regarded" as precious, it sticks in people's minds, for decades.
That's all.
But yes, there are instances where a certain product, etc, is in actuality a justafiably born "gem".
However, in the case of Marantz, and as previously mentioned, it's a bit overblown.
And those Harman Kardon Citations are in the same ballgame, as are others like Heathkit, Dynaco, etc.
There are only so many ways to design an amplifier, but slapping a name on it somehow makes it sound and perform better.
Granted, they can perform well, and with some anti-cost-cutting, even better.
But you have to put aside "the name" and look at it deeper, in a generic way.
Just like anything else on the planet, including gold, silver, diamonds....Mercedes Benz, Audi.... Apple, Samsung....... you get the idea?
It's marketing, plain and simple, consumerism at its finest.
And once something is "regarded" as precious, it sticks in people's minds, for decades.
That's all.
But yes, there are instances where a certain product, etc, is in actuality a justafiably born "gem".
However, in the case of Marantz, and as previously mentioned, it's a bit overblown.
And those Harman Kardon Citations are in the same ballgame, as are others like Heathkit, Dynaco, etc.
There are only so many ways to design an amplifier, but slapping a name on it somehow makes it sound and perform better.
Granted, they can perform well, and with some anti-cost-cutting, even better.
But you have to put aside "the name" and look at it deeper, in a generic way.
Broskie's CCDA delivers the goods, the Marantz 7have lots of followers and is muh cloned in Manila along with the AR SP3....but as for me, i was never a fan of the 12ax7 since the start, i use them in guitar amps.....the old technology in the Marantz 7 and SP3 used a global feedback network to tame the gains to line levels for an otherwise high voltage gain circuit.....
but tbh, a lot are still amazed by how these amps sound...
but tbh, a lot are still amazed by how these amps sound...
I’m curious why the 12AX7 seems to be getting such a bad reputation. Is it not linear? Does it not perform well? It was used all over the place. If it was so bad then why did so many designers choose it?
who says bad rap? it is just a matter of preference, the 12ax7 is still the go to tubes for phono preamps as no other tube types have the same mu....guitar amps use them widely...
my reasoning is based on, " why use a tube with a high gain and then use feedback to lower its gain?" when there are much simpler solutions available like the Broskie ccda?
my reasoning is based on, " why use a tube with a high gain and then use feedback to lower its gain?" when there are much simpler solutions available like the Broskie ccda?
In this case its about its specific use. As a high mu VA its fine, as a CF, not so much.
For high mu amplification, a pentode can replace two triodes easily.
Just look at the pro- preamps. Pentodes like EF86 are the ones that rule that kingdom. 12AX7 was used with cheap consumer gear. Professional gear used completely different tubes. And voila- what kind of type was a Marantz 7? Correct, consumer type. Therefore stuffed with 12AX7.
Even guitar amps use pentodes for high mu amplification.
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A Guest Article from Mr. Shirokazu Yazaki: “My Adventure With My Old Marantz Model 7” Part 3. - Jeff's Place
Meanwhile, Kato-san described with his words how in the PS-6C that V3 is replaced by a 6DJ8 tube, and as a result the output impedance is much lower compared to a 12AX7.
Generally speaking, the lower output impedance tubes would be better for driving later tubes forcefully, and I agree with that. In such a point of view, the sensitive tube, 12AX7 would not to be the best tube for using as the cathode follower circuit, and so the engineers at Audio Research obviously made a decision to use a 6DJ8 instead of 12AX7 for V3.
I've been reading this, and I'll go to sleep easy, I trust the 12AX7 unconditionally, I used it in the first hi-fi tube amp I ever built. On the preamp, of course.
That is why I have an intense love relationship with him, even though he is very small ......... but they can look for something that is better adapted according to individual needs .
Meanwhile, Kato-san described with his words how in the PS-6C that V3 is replaced by a 6DJ8 tube, and as a result the output impedance is much lower compared to a 12AX7.
Generally speaking, the lower output impedance tubes would be better for driving later tubes forcefully, and I agree with that. In such a point of view, the sensitive tube, 12AX7 would not to be the best tube for using as the cathode follower circuit, and so the engineers at Audio Research obviously made a decision to use a 6DJ8 instead of 12AX7 for V3.
I've been reading this, and I'll go to sleep easy, I trust the 12AX7 unconditionally, I used it in the first hi-fi tube amp I ever built. On the preamp, of course.
That is why I have an intense love relationship with him, even though he is very small ......... but they can look for something that is better adapted according to individual needs .
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> For high mu amplification, a pentode can replace two triodes easily.
An interesting assertion.
An interesting assertion.
" The 12AU7 is a miniature medium-mu twin triode. This tube finds use as a phase-inverter/splitter in push-pull amplifier circuits in ac/dc radio equipment and in many diversified applications..........."
The ’12AU7′ Tube - Effectrode.
But 12AU7 is the classic tube after 12AX7 to be the PP driver ....., you say two 12AU7 chained?
I don't think I've ever seen that and it wouldn't work, there isn't enough gain to use it as an input tube on a magnetic phono cartridge. ....
Maybe with a ceramic capsule?
I'm willing to see a circuit like this, you always learn something new.
Rk 2X rp and Rl 2X Rk were the rules. Zout ~ 1/gm so a 12AX7 CF would be deemed perfectly fine with 200K load presented by a tube power amplifier with short interconnect cable and probably manage a few volts swing with reasonable distortion into a 20K load despite severe AC loadline rotation.
In theory a cathode follower can be linearized using a negative rail on Rk (or pentode CS) - but does that make it sound more "transparent" ?
With tube preamplifier, power supply and decoupler impedance can influence the way a design is subjectively perceived and suspect to some degree can be deliberately tuned to taste.
C7 spawned things like Conrad Johnson and ARC's early efforts. Al Hart's Grommes cascode 12AX7 phono preamp spawned- Precision Fidelity C7, Trevor Lees PAS mod., etc.
In theory a cathode follower can be linearized using a negative rail on Rk (or pentode CS) - but does that make it sound more "transparent" ?
With tube preamplifier, power supply and decoupler impedance can influence the way a design is subjectively perceived and suspect to some degree can be deliberately tuned to taste.
C7 spawned things like Conrad Johnson and ARC's early efforts. Al Hart's Grommes cascode 12AX7 phono preamp spawned- Precision Fidelity C7, Trevor Lees PAS mod., etc.
I remember being interested in building the RCA phono pre and having come across the "insurmountable" data of the load output impedance, 220000 KOmhs !
Here is a modified Marantz 7 circuit:
Marantz 7 RIAA Phonograph Preamp – Preservation Sound
Here is a modified Marantz 7 circuit:
Marantz 7 RIAA Phonograph Preamp – Preservation Sound
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no, thats both not what I said and not what I meant.
Look here then. Its the Marrantz as it is (or at least one interpretation)
Looking at the devices that are the output of the RIAA stage and the output after the frequency network, they are the two sections of one 12ax7, both set up as cathode follower. This use would be far better served by a different, lower mu device capable of more current. The 12au7 would suit, as would many others.
Signal voltage amplification would still be carried out by the 12ax7 devices.
aardvarkash10 :
Clarified then, my lack of perfect English is sometimes open to misinterpretation. That's why I uploaded that circuit, all tubes are 12aX7 Nothing 12AU7.
I have the original Marantz 7 circuit somewhere, I'll look it up and upload it to compare with that supposed "upgrade". Many people make modifications that they claim to be miraculous. But nobody does A / B testing and measurements to prove it. I once did the "upgrade" of the xover of a JBL cabinet, (only the change of the tweeter capacitor) but I forgot to do one, listen, and then make a decision:
Back to the ancients? Advance with the other unit because the result is clearly favorable? For whose ear? I did both at the same time ..... fear of failure? Self-deception? Denial of wasting time? I still have the PIO capacitors and they measure exactly 6 uF, after more than 40 years, but now there are supposed to be more "details" with the replacements by Clarity Cap ...... Another pending task, I can still play with them I still have them.
Clarified then, my lack of perfect English is sometimes open to misinterpretation. That's why I uploaded that circuit, all tubes are 12aX7 Nothing 12AU7.
I have the original Marantz 7 circuit somewhere, I'll look it up and upload it to compare with that supposed "upgrade". Many people make modifications that they claim to be miraculous. But nobody does A / B testing and measurements to prove it. I once did the "upgrade" of the xover of a JBL cabinet, (only the change of the tweeter capacitor) but I forgot to do one, listen, and then make a decision:
Back to the ancients? Advance with the other unit because the result is clearly favorable? For whose ear? I did both at the same time ..... fear of failure? Self-deception? Denial of wasting time? I still have the PIO capacitors and they measure exactly 6 uF, after more than 40 years, but now there are supposed to be more "details" with the replacements by Clarity Cap ...... Another pending task, I can still play with them I still have them.
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A very strange discussion.
One asks how the Maranz 7 is compared to present preamps. Then a confused ans bias discussion start discussing merits of components. The REAL issue is how it sounds
compared to present offerings.
One asks how the Maranz 7 is compared to present preamps. Then a confused ans bias discussion start discussing merits of components. The REAL issue is how it sounds
compared to present offerings.
If it is just to be used with ancient passive components, modern line level inputs, hooked up to a modern amplifier, then it is not going to be that impressive, I presume. Much like using that old Mercedes for the 200km daily commute.
since "how it sounds" very much depends on who is listening, that discussion is even more pointless than the one that evolved.
Do you KNOW that ? Does anyone actually know how it sounds
and how accurate it is in delivering music ? Or are everyone only speculating
on technical grounds without even used one ?
I don't, but my comment was more about the yardstick being used to compare the performance,
'How does it sound' is not going to draw any specific responses.