Jump to content

Any Marantz 8B Users Out There


KT66

Recommended Posts

I had a Marantz 8B that I enherited from my father. I traded it on a McIntosh MC250 and never looked back. It was used with Altec Malibu speakers. The 8B is a fine amp but not worth nearly what they go for now. I am a SS amp fan, so I'm biased though! I got tired of all the heat it made. If you look at my person wab site (see below), you will see by fathers cabinet and the compartment it was housed in. Mu MC50 and MC250 are both in the same compartment now. To spite big ventilation holes, it got so hot the pitch inside the transformers melted and started to run out through the bottom! I also would burn my fingers every time I tried to adjust the bias pots.

Al K.

Link to comment
Share on other sites

Hi KT66, and welcome!

I have a great deal of experiance with Marantz 2, 5, 8, 8b, 9A and 9R amps. First let me say that I've used them with Heresy's, LaScala's, and Klipschorns. The 2's and 9's have a switch for Ultra Linear or Triode operation, and the 5's and 8's can be internally wired for triode operation. IMHO, the sound is better in this mode. The soundstage opens up, harmonic structure sounds right, voices sound more natural, etc. One thing I've always admired about the Marantz tube amps is their uncanny ability to make the speakers disappear and create a wall of sound, wider than the speaker array. They also have a nice, deep soundstage, without sacrificing focus.

If you're using Marantz tube amps, feel free to contact me directly for some suggestions or info. As you can tell, I really like them. PWK told me (1972) that many Klipsch employees used them with Heresy's. He confided that people favored the model 9 over the McIntosh 275 in his tests. Being the proud owner of both the McIntosh and Marantz units and having compared them directly on Khorns, I have to agree.

DrDave

Link to comment
Share on other sites

Al,

From one engineer to another, I admire your crossover designs very much, but have to disagree with you about Marantz tube amplifiers.

I have 3 Marantz 8b's (and multiples of all other Marantz tube models) and have serviced or updated many more over the past 35+ years, and have never experianced tar leaking out of a Marantz transformer. Comparing McIntosh's first generation soild-state venture (although I agree it was a good design) to the refined Marantz tube units is like comparing one of your fine crossovers to one from Radio Shack and saying they sound the same!

Marantz ran their amps (EL-34 only) class AB, unlike the cooler running class B that McIntosh used on their tube amps. I have to say that your father's amp had some fault, likely a failing selenium rectifier in the bias supply, which would account for you having to continually adjust bias, which caused tubes to draw excessive current and overheat the transformer (thus the leaking tar). A properly maintained Marantz tube amp requires only periodic checking of the bias, it should rarely drift.

From a guy with many years of Marantz amplifier experiance (and many satisfied customers), it's a very well designed unit, built to last for many years (with proper maintenance, like any tube unit).

BTW, having worked for a McIntosh dealer during the period of the MC-250 and beyond, I was in a position to make similar comparisons.

DrDave

Link to comment
Share on other sites

This from a McIntosh owner.

I have heard 8b's and 250s. They both have strong poits, however the quality of sound from the 8bs surpassed that of the 250s.

Owning Tubed Mcintosh, the 250 looks very nice as it is that same wonderful Black and Chrome. However my value is sound rather than looks. I have heard the 8bs on K-horns, LaScalas and Heresys.

The same with the 250s.

But this comes from a listener's point of view, an owner's to me, would carry more weight.

At this point to add to what I have, if I could find a great condition 250 at a low price, I would buy it for my collection.

dodger

Link to comment
Share on other sites

I run my Belles with a Marantz 8B and could not be happier. I cannot comment on the Triode operation of this amp but plan on getting it configured for that mode in the very immediate future.

As some of us have experienced, the stock squawkers in most vintage K-horns, LaScalas, or Belles are not ideal. That being said, one of the main strengths of the 8B is its smooth midrange performance, and my 8B helps curb some of the deficiencies inherent in the stock horn.

I would also have to agree with Audiokid and Dodger relative to its overall quality of sound. I also own modded Dynacos (Stereo 70s and Mark IIIs) and while both are great tubed performers, the sound quality of the 8B with Heritage speakers is in another league. In fact, no matter what preamp I paired it up with, solid state or tubed, the 8B always seemed to sound terrific, whether it be Belles, Cornwalls, RB-75s, or RC-7s. The one exception seemed to be my RF-7s, but those are fairly demanding (quirky) speakers and not really typical of the rest of the Klipsch fare.

That's why the 8B gets the Belles. 1.gif

Carl.

Link to comment
Share on other sites

May be getting a bit off the original question, but I'm driving my Cornwalls with a pair of Marantz Model 9's. I've tried both settings (referred to as 70 watts and triode on the amps). This may just be a matter of personal preference, but I've had them set to 'triode' for some time now. Just find the sound to be more pleasing. The only other amp I've used is a Marantz Model 15 - and it wasn't really much of a contest.1.gif

Link to comment
Share on other sites

DrDave,

No, there was nothing wrong with the bias rectifier. The thing simply didn't have enough ventilation. I wound up with a fan running on it continuously. I adjusted the bias so the idle currents were below normal to try to keep it cool. Without the fan it would cook! I checked the bias more often them most people. As I recall, it was stable and I just enjoyed experimenting with lower levels.

Al K.

Link to comment
Share on other sites

Currently I am also listening again to my 8B. I cannot comment on its triode performance, but the Marantz strikes me as more neutral sounding than for example the MC-30s. In that sense I'd call it more 'modern/balanced' sounding. Before adding the Behringer to my rig, I always found the amp's soundstage 'wide' rather than 'deep' (compared to the Macs), but that has changed. It's certainly an excellent amp one can be very happy with 2.gif .

Wolfram

Link to comment
Share on other sites

Read with interest every reply thanks .. you are preaching to the convered - if only I could get my hands on an 8b ..

I had been using la scalas with a CJ MV55 ( EL34, AB) triode configued, very nice but always found too bright & with sloppy bottom.. recently bought a pair of Quad II' mono blocs ( often reffered to as the British Marantz ). These are only 15W in class A and they blew the socks of the MV55 in every department.

8b's are almost impossible to get in the UK.

For heritage speakers I would think the Marantz would always be a better choice over a Mc 240/275 which would better suit lower efficiency speakers - which is what they were made for.

Link to comment
Share on other sites

----------------

On 1/27/2005 7:01:15 AM Al Klappenberger wrote:

DrDave,

No, there was nothing wrong with the bias rectifier. The thing simply didn't have enough ventilation. I wound up with a fan running on it continuously. I adjusted the bias so the idle currents were below normal to try to keep it cool. Without the fan it would cook! I checked the bias more often them most people. As I recall, it was stable and I just enjoyed experimenting with lower levels.

Al K.

----------------

Hi Al:

With all due respect, would it not been easier to enlarge the holes and add a second fan? Or as heat is known with tubes - whether "normal" or higher than usual, avoid a cabinet. My inpression was that it was due to heat that you needed to re-set bias.

I give you credit for stating an SS bias as the Poster seems to be inclined to the 8B.

Enjoy,

dodger

Link to comment
Share on other sites

Well as you may have heard I picked up a 8b two weeks ago for the astounding sum of $50. Just got a pre to go with it and am running it through KG 5.2's.

So far it's very sweet, detailed, broad soundstage. Eventually it will need a going over but I want to hear it for awhile first. One thing I have learned is that putting old gear into the hands of a competent tech is a must not only for safety's sake but the to actually hear what it sounded like when it was brand new.

I'm impressed now, if past experience is any guide I'll be bowled over when it's been gone over.

I've reached the conclusion that before I purchase any used tube gear I've got to allocate dollars for a thorough examination and more than likely a re-tube. If it's separetes you've also got to consider waht you will drive it with very closely. For example, the 8b sounds great with the Conrad Johnson PV3 on cd's, but is not as good with the phono. This can probably be corrected with some tube rolling, but I have seen some things on the web that say they are finiky as far as to what you drive them with.

Hope this helps.

Link to comment
Share on other sites

I have loved this amplifier without ever having heard it. Marantz incorporate some of the best craftsmanship I have seen in vintage designs, and that alone has impressed me. The loop hole there, is that good craftsmanship is only part of the equation and has really very little to do with actual circuit design. I just like attention to detail and cleanliness in layout.

I hope I can have one sometime in the few years or so....

Link to comment
Share on other sites

As many of you probably figured out, NOS 6CG7 and 6BH6 tubes make a big difference with the 8B. On Friday, I received some NOS RCAs for both slots (RCA 6CG7 Clear Top 1960s; RCA 6BH6 Black Plate 1950s). I just couldn't resist; I had to hear these. I put them in yesterday and fired her back up. Wow, what a difference. Talk about a smoother, dynamic and more detailed midrange (if that was possible). Props also goes out to Charlie Kittleson at Vacuum Tube Valley for his extra effort in going through boxes to find the exact tubes I wanted. VTV may be a trifle bit more than some others for NOS, but I appreciate the extra care, attention, and testing by Charlie.

As soon as some different output tubes come in, mine heads off to Dr. Dave (Audiokid) for some updating. Dave, thanks. Your many years of Marantz expertise is greatly appreciated by this fan. Any 8B owners out there contemplating a refreshing ought at least consider asking him about it. As expected from his considerable education and experience, the gentleman knows his stuff.

Carl.

Link to comment
Share on other sites

I've had some folks recommend the 6CG7 as a replacement for the 6922, the tube used in my ST-70 upgrade driver board. There must be a lot of difference between the two tubes, as the Duncan Amps Tube software doesn't show a subsitute for the 6CG7.

Ah... would love to get an 8B.

Marvel

Link to comment
Share on other sites

I received my 8B and it sound quite nice,surprisingly quiet...biasing question...they came with a set of Mullards and another set of svetlananas...whenI bias the tubes all go to the right point except one, I think it is a1...i turn the bias all the way to the right and it is still off...is this normal...do I have a bad tube etc ?? thanks

Link to comment
Share on other sites

Ben,

I suggest that you try moving another tube in that position. If you find that the position still doesn't work, then the amp needs servicing (actually, any amp that age needs restoration for troublefree operation). Does the tube in the position in question get as hot as the others? Let me know how you make out... you can contact me off the board at: dave500@frontiernet.net

DrDave 1.gif

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...