• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Opinions on Marantz 7T preamp?

guiller

guiller

Toscaninichus Australis
Hi,

I'm following with interest a local auction for a great looking Marantz 7T preamp from 1965. If the auction does not climb to the sky, I'd like to enter into it. I've read many wonderful things about this model and my main interest is in a finding a preamp with a great phono stage to replace my Nikko Beta 20 (of the mid 70's). My questions are: would this be a much better quality preamp than my Nikko? Are there any issues I should be aware of so as to ask the seller before the end of auction (e.g, older transistors being more noisy?)?

Many thanks in advance for any feedback!

PS: there is another preamp on auction, a Marantz 3800. Which one would be more desirable between the two? The asking price is not cheap....
 
Last edited:
Register to hide this ad
I had a marantz 3800 and I thought it was one of the biggest pieces of crap I ever owned. Slide controls are not as good as rotary controls. I since bought a 7t, and love it. The 7t will always be worth more, and I believe they have a better phono stage than the 3800, but I don't have a turntable and no desire to ever add one. One look inside each and I assure you, you would pick the 7t right off. They are hand build without printed circuit boards (point to point) Easier to access for repair, and it doesn't have a stupid Dolby meter and controls which are pretty much useless. But that's my opinion! Good luck either way. Chris
 
Something I wrote up and had been saving for my own 7T thread:

The Marantz 7T was released with much fanfare in 1966 as the successor to the famed tube-type Model 7 preamplifier (often erroneously called the 7C), to which it was cosmetically very similar. The 7T featured the same incredible build quality as the other earlier tubed Marantz equipment, but incorporated space age transistors.

One strain of thinking says that the 7T was a failure. The solid state technology, still in its infancy, was clobbered by the work of art that had preceded it and, to hear the tale, 7T buyers were lined up around the block to trade it back in for their old tube preamps.

The other side of the coin doesn’t make as good of a story. The 7T wasn’t made for as long as the Model 7, but its discontinuation in 1970 probably had a lot to more to do with the hastening product cycle of hi-fi, cost cutting, and moving production to California and Japan than it had to do with any lack of quality. The 7T was well-reviewed upon release and enjoyed in the homes of Saul Marantz, Louis Armstrong and many others.

Today, four decades later and largely removed from the context of being symbols of the move to solid state, people are still enjoying their 7Ts. Some claim to like them better than many of the subsequent vintage Marantz preamps or that they actually sound pretty close to the Model 7, which the 7T was supposedly voiced to replicate. As the resale price of the Model 7 and other vintage tube preamps of comparably high quality continue to climb past affordability, more people are checking out the 7T to see what it has to offer. There is still a vocal contingent, though, that continue to decry it as an example of everything wrong with the first crop of transistorized audio gear.
 
Last edited:
Unfortunately, I can’t give my opinions on the stock 7T. I acquired mine in non-working condition in the fall of 2008. I had been looking for a Marantz 3600 or 3800 to match my amplifier, but upon finding the 7T for a song, I decided to keep it and have it overhauled.

I saw a glowing review of Stephen Mantz’ work on the Marantz 7T on the diyaudio.com forums and decided to give him a call. Mr. Mantz is the president and head engineer for Zed Audio. It may not be household name, but Zed Audio has designed and manufactured a number of recognizable products, including the early Hifonics automotive amps and the Harman/Kardon Citation 5.1 and Citation 7.1 power amplifiers. Steve has been tinkering with the Marantz 7T since it was nearly new and has taken a personal interest not only in restoring them, but in implementing a number of modifications he’s developed over the years. He seemed like the natural choice to work on the preamp. The price quoted seemed very reasonable to me – Steve explained that he only took on vintage pieces as a labor of love. When the work was finished, he provided me with 17 pages of graphs and charts documenting nearly every facet of my 7T’s performance.

Work performed by Stephen Mantz at Zed Audio in December 2008:

1. Power supply has been upgraded and redesigned, down to just the original transformer
2. Additional power regulation has been implemented in the RIAA stage
3. All capacitors in the signal path have been replaced with new film or electrolytic types
4. All transistors have been replaced with new low noise, high Ft, high gain types
5. Faulty volume control potentiometer was replaced
6. RCA connectors have been replaced with new high quality gold-plated ones
7. The scope outputs have been rewired to the main 20db gain stage, bypassing the final high pass/low pass filters
8. The controls have been cleaned and lubricated

At that time, the following options were declined:

1. The addition of a moving coil phono amp
2. Modifying the volume control to function as a variable shunt
3. The replacement of additional passive components

Eventually when I get a wider rack built, I'll show you how the 7T looks in the WC-2 walnut cabinet and while I have it unhooked, I'll take some pics of the insides.

attachment.php
 
Last edited:
spartanmanor said:
So how do you like your refurbed 7T winters?
Click to expand...

I love it. In the absence of real competition, I don't suppose that means much.

You often hear the words "grainy" and "harsh" used to describe early SS gear. I think you'd be hard-pressed to come up with that listening to my 7T. I feel that it's detailed and transparent from top to bottom. The phono stage seems particularly good.

The build on the 7T is nothing short of fantastic. The pots are smooth, the rotary switches are solid, and the engraved faceplate is dead sexy. It's "heirloom quality" and shames the Marantz gear of the 70's (which I also love) when it comes to design.

Of course, "audiophilia nervosa" has set in somewhat. I feel like my upper mids might be sort of dry and reticent. I'd like to rule out problems with caps or drivers in my AR-9 before I start auditioning other preamps or springing for a tube buffer, though. If (and the idea pains me, even as a last-ditch scenario) I decide eventually on another preamp with a more lush midrange, the fault may lie entirely on my hearing and preferences, rather than with the 7T.

Since I'm horizontally bi-amping the AR-9 with two different power amps and have my choice of three different levels of gain (high, low, and the new "lab" outputs) or combinations of two different levels, I've got a lot of experimenting to do to find what will sound best.
 
Good review, thanks! I have an 8b and wish I could afford a 7c but a 7t would be more in line with my budget. Maybe one day I will come across one at a estate sale where no one knows what they have.
 
Very simple mod that will knock your socks off on the 7T....

Bypass the head phone jack for R and L positive wires with a .1uF film cap. Or bypass it totally.... There are switch contacts in the headphone jack that do not like "time" (meaning they lose conductivity) and high frequencies...

The head phone jack is in the signal path to main outputs.

Also, I treated the transistor leads with Silclear. I still have the stock transistors. The sockets are 40 years old at this point. They need some help with conductivity.

Recapped the electrolytics fully, look for the 4 small tantalums and make sure you replace them.

And the complete De-oxit is needed.

Do I like it ? Love it....


enjoy....

jk
 
Last edited:
Many thanks to all who gave their very interesting opinions and shared their experiences! I find them very valuable, thanks again!
 
jstang said:
Very simple mod that will knock your socks off on the 7T....

Bypass the head phone jack for R and L positive wires with a .1uF film cap. Or bypass it totally.... There are switch contacts in the headphone jack that do not like "time" (meaning they lose conductivity) and high frequencies...

The head phone jack is in the signal path to main outputs.
Click to expand...

Hmm. Does this mean the output is cut on the stock unit when headphones are plugged in?

Maybe mine's already had work in this area. It outputs a signal regardless of whether it has phones plugged in. I've always thought the headphone output was only passable, though.
 
winters860 said:
Hmm. Does this mean the output is cut on the stock unit when headphones are plugged in?

Maybe mine's already had work in this area. It outputs a signal regardless of whether it has phones plugged in. I've always thought the headphone output was only passable, though.
Click to expand...


Yes the power amp is suppose be cut out once the headphones are plugged in.


jk
 
Marantz7t15 said:
I had a marantz 3800 and I thought it was one of the biggest pieces of crap I ever owned. Slide controls are not as good as rotary controls. But that's my opinion! Good luck either way. Chris
Click to expand...

Opinions sure do vary. I think the 3600/3800 is a great preamp. As far as sliders my system doesn't require that I use them. Is the little 3600 as good as my Audible Illusions L1? Well no but with my Marantz amp and the system I use it on I would say for this system yes it is. It's all about system synergy. But to say biggest piece of crap I think wow you must have traveled down a very short road because there are some real pieces of crap out there.

Now for the 7t it has a great rep and I would consider it another nice example of vintage Marantz. But for SS I myself would pair the 7t with a nice tube amp but again thats just me.

Good Luck.
 
Stormin said:
Opinions sure do vary. I think the 3600/3800 is a great preamp. As far as sliders my system doesn't require that I use them. Is the little 3600 as good as my Audible Illusions L1? Well no but with my Marantz amp and the system I use it on I would say for this system yes it is. It's all about system synergy. But to say biggest piece of crap I think wow you must have traveled down a very short road because there are some real pieces of crap out there.

Now for the 7t it has a great rep and I would consider it another nice example of vintage Marantz. But for SS I myself would pair the 7t with a nice tube amp but again thats just me.

Good Luck.
Click to expand...
Stormin, I thought mine was a piece of crap for a number of reasons which included the slide controls. I also didn't like the fact that it only had 2 aux inputs. The bulbs are soldered in and hard to get to for replacement. I had no interest in tape decks, so the Dolby was a stroll down memory lane that took up useful space on the control panel. Didn't like at all, the fact that you go from your preamp to the amp with patch cords and then from the amp to the back of the preamp with speaker wire, and then from the preamps speaker outputs to the speakers. Way too complicated. I really thought that Marantz started going south when the started in with those stupid darn slide controls. They are not as precise as the rotary controls and are way easier subjected to dust contamination and consequently, noise. Other than that, they are good units that are American made!
 
Last edited:
Stormin said:
Opinions sure do vary. I think the 3600/3800 is a great preamp. As far as sliders my system doesn't require that I use them. Is the little 3600 as good as my Audible Illusions L1? Well no but with my Marantz amp and the system I use it on I would say for this system yes it is. It's all about system synergy. But to say biggest piece of crap I think wow you must have traveled down a very short road because there are some real pieces of crap out there.

Now for the 7t it has a great rep and I would consider it another nice example of vintage Marantz. But for SS I myself would pair the 7t with a nice tube amp but again thats just me.

Good Luck.
Click to expand...
Stormin, I thought mine was a piece of crap in terms of Marantz gear for of a number of reasons which included the slide controls. I also didn't like the fact that it only had 2 aux inputs. The bulbs are soldered in and hard to get to for replacement. I had no interest in tape decks, so the Dolby meter and controls were a stroll down memory lane that took up useful space on the control panel. Didn't like at all, the fact that you go from your preamp to the amp with patch cords and then from the amp to the back of the preamp with speaker wire, and then from the preamps speaker outputs to the speakers. Way too complicated. It's a unit that boosts that typical Marantz quality, it just didn't suite me and wound up being a real disappointment.
 
Marantz7t15 said:
Stormin, I thought mine was a piece of crap for a number of reasons which included the slide controls. I also didn't like the fact that it only had 2 aux inputs. The bulbs are soldered in and hard to get to for replacement. I had no interest in tape decks, so the Dolby was a stroll down memory lane that took up useful space on the control panel. Didn't like at all, the fact that you go from your preamp to the amp with patch cords and then from the amp to the back of the preamp with speaker wire, and then from the preamps speaker outputs to the speakers. Way too complicated. I really thought that Marantz started going south when the started in with those stupid darn slide controls. They are not as precise as the rotary controls and are way easier subjected to dust contamination and consequently, noise. Other than that, they are good units that are American made!
Click to expand...

I do agree with you that the sliders aren't near as nice as the rotary controls. As far as preamp to amp with patch cords yes. But from amp to back of preamp with speaker wire is an unnecessary step that I myself do not take. I just take my speaker cables from amp directly to my speakers.
 
Winters, that is one sweet looking unit! Any chance you can show us under the hood with the remodel? Guiller, be sure to let us know what you ended up with, by showing some photos here, Okay?
 
Stormin said:
I do agree with you that the sliders aren't near as nice as the rotary controls. As far as preamp to amp with patch cords yes. But from amp to back of preamp with speaker wire is an unnecessary step that I myself do not take. I just take my speaker cables from amp directly to my speakers.
Click to expand...

I suppose what really pissed me off was that I bought it on ebay for premium, based on a premium description, and when I got it, it didn't work right and had a bit of rust. This also contributed to the bad taste in my mouth I guess.
 
Interesting thread! I just picked up a 7T (with box) and 8B from a friend of mine who was moving and did not know what to do with them (they were his dads). He knew I was a tube fan and sold me the pair for $1,000 which he was glad to get and I thought was a steal! It will be some time before I get to tinkering with this new set but thought I'd check with 'y all and see what kinds of comments were out there.
 
Both units are great...and Not to ignore the 8b, but have you peeked inside the 7t yet? You will be surprised if you have never seen the internals of one.

Jk
 
You must log in or register to reply here.
Back
Top Bottom