Jump to content
The Klipsch Audio Community
Sign in to follow this  
bharat

Diving into tube amp world with Marantz 8

Recommended Posts

I have a pair of Forte II paired with a Marantz 2325 and absolutely love the sound! I have been thinking about diving into the world of tube amps for a while now and finally bit the bullet and picked up a Marantz 8 from 1959 and it seems to be in great condition (I will know for certain next week when it is in my hands). My question to the group is whether or not my Forte II would be a good speaker match to stand up to the Marantz 8 and fully obtain that warm amazing tube sound that all of you talk about so much? I plan to use my 2325 as a pre-amp until I can afford a tube pre-amp. Look forward to hearing from the group. I will post some photos later tonight.

 

Bharat

  • Like 2

Share this post


Link to post
Share on other sites

Should be a very nice match between the two.  I believe that Thebes has either an 8 or 8B that he runs with his speakers, so he could probably let you know what to expect.  With a unit such as that, I would recommend installing the best NOS tubes you can afford.

 

@thebes

  • Like 1

Share this post


Link to post
Share on other sites
4 hours ago, bharat said:

I have a pair of Forte II paired with a Marantz 2325 and absolutely love the sound! I have been thinking about diving into the world of tube amps for a while now and finally bit the bullet and picked up a Marantz 8 from 1959 and it seems to be in great condition (I will know for certain next week when it is in my hands). My question to the group is whether or not my Forte II would be a good speaker match to stand up to the Marantz 8 and fully obtain that warm amazing tube sound that all of you talk about so much? I plan to use my 2325 as a pre-amp until I can afford a tube pre-amp. Look forward to hearing from the group. I will post some photos later tonight.

 

Bharat

It should be quite good sounding. If it has not been checked out by a competent tech I'd do that before you power it up.

  • Like 1

Share this post


Link to post
Share on other sites
On 10/15/2019 at 2:29 PM, bharat said:

I have a pair of Forte II paired with a Marantz 2325 and absolutely love the sound! I have been thinking about diving into the world of tube amps for a while now and finally bit the bullet and picked up a Marantz 8 from 1959 and it seems to be in great condition (I will know for certain next week when it is in my hands). My question to the group is whether or not my Forte II would be a good speaker match to stand up to the Marantz 8 and fully obtain that warm amazing tube sound that all of you talk about so much? I plan to use my 2325 as a pre-amp until I can afford a tube pre-amp. Look forward to hearing from the group. I will post some photos later tonight.

 

Bharat

 

Great find, that Amp will go together with Klipsch speakers like butter on hot toast.

 

Wb

  • Like 1

Share this post


Link to post
Share on other sites

I see capacitors and diodes which absolutely must be replaced to ensure long term longevity.  Be careful if you are going to continue using the amp in its present state.

 

Maynard

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, tube fanatic said:

I see capacitors and diodes which absolutely must be replaced to ensure long term longevity.  Be careful if you are going to continue using the amp in its present state.

 

Maynard

Thank you for the insight Maynard. May I ask for a bit more specifics on this? Do you mean that capacitors and diodes are old and therefore need replacement? Or do you mean that someone may have replaced them with incorrect / not ideal ones and I should try to restore back to as close to original state as possible? 

 

Thanks in advance for your help. Bharat

Share this post


Link to post
Share on other sites

Except for 3 metal film resistors (the tiny blue ones), the underside looks totally original with a quick perusal.  All of the capacitors under the chassis, and the two "can" type caps on top, need to be replaced as well as the solid state power supply diodes.  The resistors need to be checked to see if they are within tolerance as many tend to drift to the high side of their value over time.   It's wonderful that you have a unit which has not been butchered over the years; but, a full restoration by a competent technician is definitely in order.  Once done you will have an amp which I suspect you will never want to part with!

 

Maynard 

Share this post


Link to post
Share on other sites

Thank you sir for the super helpful information regarding the amp. I am located in Portland, Maine and would welcome some recommendations for competent technician who maybe located relatively nearby. Thanks in advance.

 

Bharat

Share this post


Link to post
Share on other sites

Send an email to Bob Latino ( Bob01605@aol.com).  I’m confident he can hook you up with a very capable tech within a reasonable distance.  

 

Maynard

  • Like 1

Share this post


Link to post
Share on other sites

As I seem to recall, Marantz 8Bs were $249 new.

 

Do not assume, as you seem to have done, that adding a tube type preamp to your new tube amp, will be an automatic overall gain .   

 

Why ??  There are numerous high quality solid state phono units being made today, which, when combined with a good tube amp, may likely give you the best overall possible result.

 

If you do not use Phono as a source, consider using no preamp, JUST a high quality passive attenuator and a source selector, as it can ELIMINATE un needed gain stages, which typically add to the signal's degradation.

 

Try to keep your system, and audio path high quality - but simple.

 

Jeffrey Medwin

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

I have an 8 (not the b) that I run with Cornwalls.  It is a fantastic sounding amplifier to my ears.  After having it a while I put in quad of Mullard El34s and the sound improved over the tubes that came with it.  I got a ton of information about the marantz 8 at AK.  Here is a link about newer tubes that work well in the 8 or 8b:

https://audiokarma.org/forums/index.php?threads/best-new-el34s-for-8b.880974/#post-13010239

 

There is a member there, crooner, who restores vintage marantz tube units.  He had some recs about what to replace, what to leave, etc; I guess in an effort to not change the overall sound.  Not that his suggestions were the only ones I read about or were recommended but he did a restoration of a marantz 7 tube pre-amp that was really well thought out and planned, so I felt comfortable with his recs.  Here is that thread link - https://audiokarma.org/forums/index.php?threads/ultimate-marantz-model-7-restoration-thread.727823/

 

I know that just for starters, as mentioned above, he recommended replacing the bias supply power caps (he actually said the old top hat diodes are fine and to leave them) and the cathode resistors.  He is a big fan of leaving the Good-All caps in place as well.  He also recommended using  EF90 tubes as a replacement for the 6BH6, they have the mesh plate and are made in Holland.  

 

Congrats on obtaining a great amplifer, I'm sure you will love it.

 

Tom

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

Not to be argumentative, but the Good-All caps as well as the Sprague Black Beauty caps are very prone to value drift and failure.  Given how inexpensive modern replacements are it is foolish to leave those in.  The same goes for the old type diodes.  A modern 4 cent replacement will do the job nicely.  

 

Maynard

Share this post


Link to post
Share on other sites
7 hours ago, tube fanatic said:

Not to be argumentative, but the Good-All caps as well as the Sprague Black Beauty caps are very prone to value drift and failure.  Given how inexpensive modern replacements are it is foolish to leave those in.  The same goes for the old type diodes.  A modern 4 cent replacement will do the job nicely.  

 

Maynard

I 100% agree with you and I am certainly not being argumentative.  I am not an expert or fanatic on these things or pretty much anything for that matter.  Some people want the good-alls in and some want them out - I would say if they are replaced, just keep them.  If for some insane reason you decide to sell the amp, some of the people/collectors that value the original stuff would want them and may pay more for having them.

 

Heck if you are going to replace them just use these, the "super" capacitors that some of the Japanese restorers swear by.  https://www.partsconnexion.com/arizona-film-capacitors.html

Again I do not have an opinion on them and I do not condone, endorse, or swear by them.  I have read some info and read about others that have used them and their enjoyment of them, but I have not heard any amps with them.  And probably with my hearing loss, I doubt I could tell a difference if there is in fact a difference.  Fortunately I do not have golden ears because it would mean this hobby could possibly become even more expensive. 

Share this post


Link to post
Share on other sites
On 10/17/2019 at 4:49 PM, tube fanatic said:

Except for 3 metal film resistors (the tiny blue ones), the underside looks totally original with a quick perusal.  All of the capacitors under the chassis, and the two "can" type caps on top, need to be replaced as well as the solid state power supply diodes.  The resistors need to be checked to see if they are within tolerance as many tend to drift to the high side of their value over time.   It's wonderful that you have a unit which has not been butchered over the years; but, a full restoration by a competent technician is definitely in order.  Once done you will have an amp which I suspect you will never want to part with!

 

Maynard 

I agree technically of course with replacing all the caps, diodes, and out of spec resistors. The amp should not be used or even turned on as is. But at the same time, it is such a shame to ruin the authenticity. This amp is a real thing of beauty as is. Just looking at the effort put into hand wiring and routing of component leads and the way the labels are all aligned tells of a time of great pride in craftsmanship. It is a work of art. I would hate to see those beautiful vintage components replaced with modern equivalents. Just look at how the few blue metal film resistors and pink heat shrink stand out like sore thumbs. It is fairly easy to restore this amp electrically to like new condition for very little money, and I'm sure it will sound amazing, but it is almost certainly worth more in its current state. It's a tough decision for sure. If you do choose to restore it I would look for replacement parts that resemble the vintage components, i.e., use high quality new carbon resistors, and axial capacitors where available. The cans could be re-stuffed with new electrolytics, etc. Great find and best of luck!

  • Like 2

Share this post


Link to post
Share on other sites

Out of all the replies to this thread, what Tom1066 said rings truest to "me",  about Crooner's ( seemingly experienced ) 8B updating approach.  

 

I feel, one should not try to change " all the caps" or " all the resistors",  as SOP - standard operating procedure,  because it changes the SOUND of the stock amplifier.

 

However :  

 

One can MEASURE, individually, methodically, all the caps, as to their uF value, and measure each cap as to their ESR , and determine if ANY are way out of spec, and needing attention. 

 

Likewise, one can easily MEASURE, individually, methodically, all the resistors, to see if they drifted, and vary greatly from their intended ( schematic ) values.

 

- - - - - - - - - - -

 

There MAY possibly be no parts that are GROSSLY out-of-spec.  This might take up to 3 hours of time / labor to do and carefully document these measurements in 2019, VS this piece being around and unchanged, virgin,  since about 1959 ... six decades !!

 

- - - - - - - - - - -

 

I am sure I personally could  easily improve upon the sound of this amp, by using well-thought-out new film caps, and highest-quality resistors. 

 

But then, it is no longer a Marantz 8B one is listening to.  That's the RUB !!!!

 

Have fun, but think twice, before acting.  Its up to the Original Poster.   This is just little-ole-me's " two cents " worth of thoughts. 

 

Jeffrey  Medwin

 

 

  • Like 2

Share this post


Link to post
Share on other sites
6 hours ago, Jeffrey D. Medwin said:

Out of all the replies to this thread, what Tom1066 said rings truest to "me",  about Crooner's ( seemingly experienced ) 8B updating approach.  

 

I feel, one should not try to change " all the caps" or " all the resistors",  as SOP - standard operating procedure,  because it changes the SOUND of the stock amplifier.

 

However :  

 

One can MEASURE, individually, methodically, all the caps, as to their uF value, and measure each cap as to their ESR , and determine if ANY are way out of spec, and needing attention. 

 

Likewise, one can easily MEASURE, individually, methodically, all the resistors, to see if they drifted, and vary greatly from their intended ( schematic ) values.

 

- - - - - - - - - - -

 

There MAY possibly be no parts that are GROSSLY out-of-spec.  This might take up to 3 hours of time / labor to do and carefully document these measurements in 2019, VS this piece being around and unchanged, virgin,  since about 1959 ... six decades !!

 

- - - - - - - - - - -

 

I am sure I personally could  easily improve upon the sound of this amp, by using well-thought-out new film caps, and highest-quality resistors. 

 

But then, it is no longer a Marantz 8B one is listening to.  That's the RUB !!!!

 

Have fun, but think twice, before acting.  Its up to the Original Poster.   This is just little-ole-me's " two cents " worth of thoughts. 

 

Jeffrey  Medwin

 

 

 

 

^^^ This! ^^^

 

Wb

Share this post


Link to post
Share on other sites

Jeff, the problem with measuring capacitors with a meter is that it tells you nothing about what they will do in the presence of high voltage DC ( plate bypass, coupling, etc.).  I have experienced many which measure fine but fail under that condition.  Also, many vintage caps will change value considerably with large temperature variations.   

 

I agree with rjp’s appreciation of the meticulous factory appearance.  However, is it better to have a work of art which may burn up with use, or a modernized equally artistic rendition which will work flawlessly for many more decades?  As to the amp being worth more in its current state that, of course, is a totally individual choice.

 

Maynard

Share this post


Link to post
Share on other sites
34 minutes ago, tube fanatic said:

Jeff, the problem with measuring capacitors with a meter is that it tells you nothing about what they will do in the presence of high voltage DC ( plate bypass, coupling, etc.).  I have experienced many which measure fine but fail under that condition.  Also, many vintage caps will change value considerably with large temperature variations.   

 

I agree with rjp’s appreciation of the meticulous factory appearance.  However, is it better to have a work of art which may burn up with use, or a modernized equally artistic rendition which will work flawlessly for many more decades?  As to the amp being worth more in its current state that, of course, is a totally individual choice.

 

Maynard

 

Maynard,

 

Do you have an older cap tester or what do you use to perform testing of old or used capacitors

 

Wb

Share this post


Link to post
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.

Sign in to follow this  

×
×
  • Create New...