7c vs & 7t Listening testing. Which one Wins...

[jstang]

Restoration includes far more than caps....you can replace with exact factory fresh original type caps and still NOT come up to the original sound.

So many electronic components beside caps degrade over time.

To assume a 46 year old unit without full and careful restoration can represent the factory is extremely misleading. You are only fooling yourself....

Would you expect an unrestored high mileage 1966 Corvette to perform like new? No....!

I would not even drive an unstored high mileage 66 Corvette on the street....

Would you power up an old unit without a variiac or dim bulb...? No...!

But yet people are afraid to do a proper refurb of a 7t.... :scratch2:

Every old Marantz I have owned, has be powered up slowly and monitored for current draw... Then tested and restored..... AND HOT RODDED....if appropriate for that unit.

The 7t is a great unit to hod rod....

Would you take two unrestored high mile muscle cars from the sixties, that have been sitting for years and try to recreate the Quarter mile times as recorded in tests from back then in the sixties? No...!

Some audio units hold up great over time and others do not... Just like cars...

Some audio units respond well to hot rodding and other do not...just like cars...

Yes at minimum my gear gets 100% tested refurbbed... And some are hot rodded...and some are restored to 100% stock....

But no way would I compare two 40 year old un-refurbbed units, that is a waste of time... If you are into archeology, then why even turn your units on?


JohnK

IMO, that is a valid opinion. It is a real assessment of an unrestored piece of vintage gear.



JK, you obviously also don't like the sound of unrestored gear. You're absolutely right about stuff not aging well. But if you "restored" the 7T with new but exactly the same type of caps, resistors, tantalum caps, etc. as was original, there's a chance the 7T could sound better than stock but still sound poorly against what we have today or know today about components.

Your restoration has come from pretty careful new and different passive component selection and listening tests plus knowledge of later circuit techniques that weren't used or available when the 7T was designed and built. If its a "super 7T", so be it. But not everyone can or wants to modify the 7T for whatever reason they have. That's their prerogative.

From what I know, Steve knows his gear, knows his sound and the sound of live and well recorded music. He does great stuff professionally and has the ability and means to do anything with gear if desired. He didn't pursue modifying the 7T, he moved on. That's ok. Your 7T was never disparaged nor commented on, he just commented on a vintage unrestored stock 7T.

 

[jstang]

You know I love what Sid was capable of... BUT....

Do you believe in the perform improvement of bypass caps for electrolytics? And how come Sid and Saul never used them?

Because the state of the art changed over time... Saul and Sid would have used Silmic and bypass caps if he known and had those improvements.... Time has given us an advantage that they surely would use today....

Jk

Sid probably would have loved it. As he was proud of his early SS achievements, even if they fell short of his tubed masterpieces.

 

[jstang]

Nothing that some Silmics and bypass caps can't fix.... And ditching the tantalums is a must these days....

As a matter of fact that is what a lot of people hear in electrolytic caps vs films.... New high grade electrolytics with film bypasses help resolve that issue...they take the harshness out of the sound.

According to several Boston Audio Society "BAS Speaker" issues (available online for download), the 7T had a reputation for sounding edgy and harsh as early as the mid 1970's. The model was less than ten years old back then.

There are also reports from well reputed sources, that when the 7T came out in December 1965 a lot of trendy folks traded their 7C's for the new model only to come back to the stores several days later wanting to buy their "old" tubed units back!

 

[crooner]

Nothing that some Silmics and bypass caps can't fix.... And ditching the tantalums is a must these days....

The 7T is full of early Siemens small film caps also. I believe those did not age as gracefully as the Good-All mylars or even the Bumblebees on the tubed gear.

 

[jstang]

Now you're egging me on.....

The 7T is full of early Siemens small film caps also. I believe those did not age as gracefully as the Good-All mylars or even the Bumblebees on the tubed gear.

 

[jstang]

Even Sid took a second bite of the apple... Riight Crooner? :yes:

http://www.audiokarma.org/forums/showpost.php?p=5690616&postcount=16

 

[jstang]

You got my gears turning...AGAIN . And this is an area that I need some schooling on....

My cheap ESR Meter does not do a good job of testing very low value films....maybe I should look for a better one.

As you mostly know already Crooner, early 10Bs have some of the same caps as the 7t....and I think the later 10B film caps are some what different too....

Both the 7t & 7c caps changed some over time as the manufactures changed their component product lines. My 7c is very very late serial number...it has a lot of different components when compared to early serial numbers..and my 7Ts have a lot of differences too with components, one is very early and the other very very late...


jk

The 7T is full of early Siemens small film caps also. I believe those did not age as gracefully as the Good-All mylars or even the Bumblebees on the tubed gear.

 

[jstang]

JK, you obviously also don't like the sound of unrestored gear. You're absolutely right about stuff not aging well. But if you "restored" the 7T with new but exactly the same type of caps, resistors, tantalum caps, etc. as was original, there's a chance the 7T could sound better than stock but still sound poorly against what we have today or know today about components.

.

Actually I do like the sound of unrestored gear... But the ones I do like usually prove to be in great shape... NOT WORN.... I usually don't like the sound of WORN or BROKEN gear....vintage or new or original or modified... if its worn out, I will not like it...

My 20 has only been cleaned and only one zener replaced....and it sounds great.... I did check every cap and voltage as listed in the SM... My 10b would hardly pick stations when I first got it and was very dusty... Needed some tubes, tuner cleaning and a few internal caps... DID I RUIN IT BY REPAIRING IT? NO! I brought it back up to spec...and looks & sounds like new.

I am working on an 18 for some one right now... I HATE THE SOUND.... You know why? Because it will not produce any sound... Should I leave it unrestored? So he can call it all original ? It has many issues that will required new caps, some resistors and maybe some semi conductors.....

The only difference between a worn degraded 7t that has not been restored and the 18 I am working.... Is that I am taking the time to bring the 18 back up to where it should be.... And the owner may choose to hot rod the 18... Its his choice, as it is not a perfectly clean unit....


FYI... Some caps sound poor from day one regardless of age or usage.... Tantalums are one of those...
Some caps sound great early in their lives, but degrade over time.
Some caps sound great early and stay that way....

Resistors tend to degrade by drifting in the values. But stay sonically close with a rise in noise. Resistor types do affect sonics...carbon composition sound very different than Metal foil....depend on the circuits.

I left the resistors and film caps stock in the 7T and focus on other areas... Some people recommend replacing the resistors in the 7t... :scratch2: the new types can sound better....

The last few pages of this has been a mixed blessing...fun but nothing really new . If people read the very first post :twak: , they would realize I never favorably compared a stock WORN 7t to the 7c.... And in fact agree a stock good shape 7t does not match up to the 7c....although I have a second VERY VERY late serial number ( 1843X ) 7t that is 100% stock ( only a light Di-oxing and all caps & voltages test fine )... Do you want me to back to back test that to my very late ( 2160X ) 7c?

The 7t is a great every day preamp....and especially one that is Modified.... :yes:

Funny, seems Sid and I agree...with the exception that I believe there is some additional improvements.... that make it "6 of one, half dozen of another"....

jk

 

[PB_Audio]

For $8000, I'll take my Marantz 7T, a Mark Levinson ML-1,
and either an ARC SP-11, SP-14 or LS-15; and I won't have to defend the sound of my system to anyone.
The Model 7/7C is great; but it's not the SOTA. Sorry...

Now, if you were talking Model 8B or Model 9...
They certainly out-class what MAC had/has to offer; and yes, that includes the MC-30, 50, 240 or 275.
I am rather fond of the MC2205/2255; but only as back-up for a properly restored Marantz Model 500.
In the end, the complete question is NOT the Marantz 7 vs the 7T; but rather the Model 7 & 8B/9 vs the properly restored 7T & 500.
Now, that is a real contest...

...oh, and guess what... they BOTH WIN!!!

 

[jstang]

Ugh....

 

[rab32chevell]

I think one point should be made about the 7t. If you are concerned about originality, buy two 7ts. One to look at, and one to listen to. Fact is, they are both going to look the same from the outside. But for the entry price of a 7t, I don't think anything on the planet would be a better investment considering the flexibility not to mention the beauty. I reason that back in the mid sixties, when these things were designed, cap designs were not well understood and the choices few. As PB and Jstang said, putting new component parts into a 7t only makes sense. And, I agree 100% about what PB said about spending huge sums of money on a 7c when you can get better pre-amps for a lot less. You can probably spend a little money refurbing a 7t and get an excellent pre-amp with all the beauty of a 7c that also sounds really good. Maybe it doesn't have the mid-range of a 7c but I'll bet that a modern referb of a 7t is not going to sound harsh and grainy like the people at BAS said. And here is another thing about that. To hear any amplifier at it's best, you must switch the power cord to find out which position is best. There is only ONE way it sounds right. Listen to your 7t with the cord in one position and then turn it upside down. The correct position will be clearly evident. Or, you can measure it. In fact, the Marantz 15 owners manual warns to mark the plug direction if you ever detach the short plug from the other amplifier so that you can plug it back in the way it came from the factory where it was measured for lowest hum etc. This is a polarity issue. The plugs in every component you have in your system should have proper plug polarity. You can buy a polarity tester from Audio Advisor that is very simple to use or you can use a regular OHM meter by putting one lead on a true ground and touch the other lead to the chasis of what you are measuring. Reverse the power plug and take another reading. The correct plug orientation is the one that gives the lowest reading. But first set the ohm meter to DC 5 volts before you start the test and disconnect the interconnect cables.

 

[Steve Hoffman]

Well, one more comment from me and then I'm out of this crazy thread.

Unless you really dig all of those endless switches, bass and treble controls and the rest of the stuff that modern audiophiles hate with a passion, why bother modding a 7T? Just get a "pure" modern unit to begin with.

Unless you're going to bypass all of that stuff on the 7T and only use the volume control and (if you must) the balance control, that might be interesting. But if you keep all of that clutter in the signal path, once again I ask? Why?

If you want to build a fine preamp, build one, use something more modern and less filled with needless stuff as your template and create a beautiful sounding preamp. But if you start with a vintage unit, you're just adding a bunch of extra gunk to the signal path, aren't you?

I like old gear to sound like old gear. I have modern gear that sounds really wonderful. Sometimes I want to hear what Grandpappy Audiophile Doctor/Dentist had back in the 1950's, etc. If I had an old Buick Skylark from 1962, the last thing I would want to do would be to pull the engine out of it and redesign the thing to make it drive better or faster or whatever. Turning it into a race car just wouldn't be my thing.

So, I guess I'm confused as to why something with a needlessly complex outdated solid state circuit with endless filter switches and tone controls would be preferred to "create" a preamp rather than say a 1996 Audible Illusions preamp template or something.

If one feels like tinkering, I guess the Marantz 7T is pretty neat, looks retro and all, but any more than that and you've lost me..

My 7C on the other hand, I love it because it sounds like 1961. That was a good year!

 

[jstang]

Other than the tube units.... I am not sure why people predent to care so much about originality. You want a broken unit? Degraded unit? Up to spec unit? Or improved unit?

Any way you look at it a 46 year old pre-amp needs to be refurbbed.

The 7c is a great preamp that I would never upgrade and would go out of my way to keep original....only stock or stock looking parts.

Guess what... I have two 7Ts for the exact reason you mention rab32... But even the very late serial has caps that are marginally good via an ESR test and would ideally need replacement.

Jk

 

[jstang]

Promise this is your last post in this thread .... CYA..... May be you understand your business or not...but you don't understand electronics...

In the car world its call "Resto-Mod"...... look it up. But your choice of 62 skylark would make for a creepy resto mod.... But that does not stop capable people from using their imaginations and skills. My imagination takes me to Resto-Mod Marantz.... I hate worn dull sounding gear....

Well, one more comment from me and then I'm out of this crazy thread.

Unless you really dig all of those endless switches, bass and treble controls and the rest of the stuff that modern audiophiles hate with a passion, why bother modding a 7T? Just get a "pure" modern unit to begin with.

Unless you're going to bypass all of that stuff on the 7T and only use the volume control and (if you must) the balance control, that might be interesting. But if you keep all of that clutter in the signal path, once again I ask? Why?

If you want to build a fine preamp, build one, use something more modern and less filled with needless stuff as your template and create a beautiful sounding preamp. But if you start with a vintage unit, you're just adding a bunch of extra gunk to the signal path, aren't you?

I like old gear to sound like old gear. I have modern gear that sounds really wonderful. Sometimes I want to hear what Grandpappy Audiophile had back in the 1950's, etc. If I had an old Buick Skylark from 1962, the last thing I would want to do would be to pull the engine out of it and redesign the thing to make it drive better or faster or whatever. Turning it into a race car just wouldn't be my thing.

So, I guess I'm confused as to why something with a needlessly complex outdated solid state circuit with endless filter switches and tone controls would be preferred to "create" a preamp rather than say a 1996 Audible Illusions preamp template or something.

If one feels like tinkering, I guess the Marantz 7T is pretty neat, looks retro and all, but any more than that and you've lost me..

My 7C on the other hand, I love it because it sounds like 1961. That was a good year!

 

[Sam Cogley]

Well, one more comment from me and then I'm out of this crazy thread.

Unless you really dig all of those endless switches, bass and treble controls and the rest of the stuff that modern audiophiles hate with a passion, why bother modding a 7T? Just get a "pure" modern unit to begin with.

Unless you're going to bypass all of that stuff on the 7T and only use the volume control and (if you must) the balance control, that might be interesting. But if you keep all of that clutter in the signal path, once again I ask? Why?

If you want to build a fine preamp, build one, use something more modern and less filled with needless stuff as your template and create a beautiful sounding preamp. But if you start with a vintage unit, you're just adding a bunch of extra gunk to the signal path, aren't you?

I like old gear to sound like old gear. I have modern gear that sounds really wonderful. Sometimes I want to hear what Grandpappy Audiophile Doctor/Dentist had back in the 1950's, etc. If I had an old Buick Skylark from 1962, the last thing I would want to do would be to pull the engine out of it and redesign the thing to make it drive better or faster or whatever. Turning it into a race car just wouldn't be my thing.

So, I guess I'm confused as to why something with a needlessly complex outdated solid state circuit with endless filter switches and tone controls would be preferred to "create" a preamp rather than say a 1996 Audible Illusions preamp template or something.

If one feels like tinkering, I guess the Marantz 7T is pretty neat, looks retro and all, but any more than that and you've lost me..

My 7C on the other hand, I love it because it sounds like 1961. That was a good year!

Would you drive that '62 Skylark on the original tires and brake lines? I think not.

 

[jstang]

I don't think they get that analogy.... .....but who cares it's the internet....

Would you drive that '62 Skylark on the original tires and brake lines? I think not.

 

[PB_Audio]

Well, one more comment from me and then I'm out of this crazy thread.

Unless you really dig all of those endless switches, bass and treble controls and the rest of the stuff that modern audiophiles hate with a passion, why bother modding a 7T? Just get a "pure" modern unit to begin with.

Unless you're going to bypass all of that stuff on the 7T and only use the volume control and (if you must) the balance control, that might be interesting. But if you keep all of that clutter in the signal path, once again I ask? Why?

If you want to build a fine preamp, build one, use something more modern and less filled with needless stuff as your template and create a beautiful sounding preamp. But if you start with a vintage unit, you're just adding a bunch of extra gunk to the signal path, aren't you?

I like old gear to sound like old gear. I have modern gear that sounds really wonderful. Sometimes I want to hear what Grandpappy Audiophile Doctor/Dentist had back in the 1950's, etc. If I had an old Buick Skylark from 1962, the last thing I would want to do would be to pull the engine out of it and redesign the thing to make it drive better or faster or whatever. Turning it into a race car just wouldn't be my thing.

So, I guess I'm confused as to why something with a needlessly complex outdated solid state circuit with endless filter switches and tone controls would be preferred to "create" a preamp rather than say a 1996 Audible Illusions preamp template or something.

If one feels like tinkering, I guess the Marantz 7T is pretty neat, looks retro and all, but any more than that and you've lost me..

My 7C on the other hand, I love it because it sounds like 1961. That was a good year!

But, does your 7C sound like it did in 1961? Likely, far from it... WHY?
You might have noticed my mention of the ARC (Audio Research Corp.) LS-15. It's known as a 'Line Stage' amp in the industry. It is probably my next preamp purchase, and is primarily what you recommend... i.e. a bare bones preamp, with no tone controls, (and also no phono preamp either). I have a large vinyl collection; but it's still packed from my last move 22 years ago. If I ever want a great phono preamp, the Mark Levinson ML-1 is hard to top.
But you won't like this... after I mod my 'new' (original) Dynaco ST-70 tube amp, I'm going to build a Marantz Model 7 'Line Stage' Amp... that's right, no tone controls, no phono stage, just inputs for a tuner and an AUX or two; but otherwise the original topology and circuit layout. AND, I won't be scrounging for 40 year old caps for the build. I'll be looking to out perform the original Model 7, not duplicate a 40 year old unit with dried out caps.
As I'm sure you know, capacitor technology has not stood still in the last 40 years. Do you suppose Sid and Saul shopped for caps from the 1940s when they built their wonderful Models 7/8b/9, etc in the 60s? I don't think so. They used the best they could buy within reason. If you value their efforts, why not adopt their design philosophy. Weren't they in pursuit of the best sound technology would allow. Personally, I very much favor that attitude.
In the end, while you're all wet when it comes to the potential of the 7T, your philosophy about losing all the junk in the preamp is a wonderful idea.:thmbsp:

 

[jstang]

The 7T & 7C share the stepped tone control design...that is bypassed totally when set to flat.... Plus the stepped design eliminated the sonic issues with Pots and large Caps in general when you do actual use the tone control... High quality Film cap and resistor in a feedback network beats a Pot and large cap every time....

But switches are switches and need cleaning. Not as much as pots....

Ditch the preamp altogether and just use the gain controls on the amp.... its as clean as you will get. I spoil myself every now and then by going direct.... Then its what drives me to improve my preamps and amps....

I was running the 8b clone that way...prior to using it with the 7c with it.... That dang straight wire will spoil you.... Would I dare say the best preamp is none at all...

jk

 

[PB_Audio]

The 7T & 7C share the stepped tone control design...that is bypassed totally when set to flat.... Plus the stepped design eliminated the sonic issues with Pots and large Caps in general when you do actual use the tone control... High quality Film cap and resistor in a feedback network beats a Pot and large cap every time....

But switches are switches and need cleaning. Not as much as pots....

Ditch the preamp altogether and just use the gain controls on the amp.... its as clean as you will get. I spoil myself every now and then by going direct.... Then its what drives me to improve my preamps and amps....

I was running the 8b clone that way...prior to using it with the 7c with it.... That dang straight wire will spoil you.... Would I dare say the best preamp is none at all...

jk

Interesting... the comparison in the late 70s with regard to preamps was with a 'straight wire'... The natural sonic goal of any SOTA wannabe preamp.
:yes:
Now, let's use shielded cable for the signal path, made of oxygen free copper, or, better still, silver wire. There is even room for improvement in the proverbial 'Straight Wire' preamp.
How about moving the power supply to its own separate case? (not a new idea... the ML-1, in fact, has a separate housing for its power supply.
Good engineering??? Oh yah, if you want low noise.:yes:

 

[onemug]

jstang, PB Audio, anybody else.....

Do you recommend exercising the "selector" or "mode" switches periodicly or is it not necessary on the 7 and 7t? Same with the 4 levers in the middle?