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Sony VFET; TAN-8550 vs. TA-N7

T

tyten

New Member
Is there anyone out there who had the opportunity to listen to both those amplifiers and actually compared the sound? I would be very eager to hear any oppinion.
If you look at the datasheet of those - the TAN-8550 is a "pure" VFET amp. with nothing in the way between the VFET and the loudspeakers (push pull). If you look at the TA-N7 there are bipolar transistor between the Drain of the VFET and the lodspeaker line. Those bipolar transistors act as a bias adjustement since the bias adjustment of TAN-8550 and the TA-5650 etc is not very good and stable unless you rebuild a little, but nevertheless they are in the loop giving certain limitations to the operating parameters of the vFET's.
The TA-N7 should therefore sound more like a normal transistor amplifier than a VFET amplifier?
 
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I share your eagerness. Owned TA-4650 TA-5650 TA-8650...TA-N7.....like the TA-5650 the most....though all are V-Fet designs.
 
I still haven't heard a VFET only design like the TA-8550 and consorts, only my TA-N7B and TA-F7B. I still think those sound like a million bucks, but apparently the older VFET line is a bit more colorised in their sound, which appeals to a lot a people.

Unda Maris has about any existing VFET amp on the planet, so I'm sure he could also shed some light on this, if he ever surfaces again :D
 
I think I am one of the few people who own TAE-7B , TAN-7B, TAE-8450, TAN-8550 , TC-880, ST 5950SD, TC something, even a ECR 500 :banana:

And finaly a SB5335, rare as hell :yes:

Believe me or not, I didnt made a side by side comparison yet, however my intial impression is that 8550 is a little bit warmer. But my TAN-7 is running very cool. and there could be a problem about the bias. I didnt have the time to check them yet also.

I will post more when I do a side by side comparison

Mertol
 
I did do the comparison

And my winner is definitely the TAN-8550. Since I own all sony v-fet amps, I have heard them all extensively. The 8550 is MUCH MORE dynamic and musical than the TA-N7, but use a good speaker and pre- amp.

I also know that the TA-N7 may need some care because of old age, but the 8550 works absolutely perfectly being even older.

Also in comparison with the Yamyam B2, the 8550 wins. The Sansui BA-1000 is much more simple design, but very a very pleasant baby of mine, now running with a passive AS Passion pre-amp. :tresbon:
 
Doesn't seem like it would be any comparison until you had every amp back to original specs... but I guess if your amps make you happy the way they are, then it doesn't matter.

However, I would worry about your beauties dying, if you don't have some safety mods performed on them...

Fitzy had his TA-N7 overhauled (as I did mine), and he actually heard before and after. He was about to discard it before the overhaul, yet now he's totally in love with it, after it's been restored... so it does make quite a difference apparently :)
 
TA-N7 rebuild

Kristof is right the upgrade/rebuild makes an amazing difference as well as giving another 30 years of service. I would advise anyone running an original N7 to get Mirko's kit post haste!
 
I own all the V-FET amps (except HA-500F) and I have to say, that for me the TAN-8550 by no means is the best sounding of them all.

The TA-N7B (fully modified) stands out of the crowd pretty easily and the only ones, which come close somehow are the B-3, the JM-S7 and the BA-1000 (because of it's unique OTL tube like "hot rod" sound). The only "classic" amps I own which exceed the TA-N7B are the MX-10000 and probably the SE-A100 a little as well. The TA-N9's in Class A mode could be also a "hot" :D candidate, but they still have to be repaired.

To me my TAN-8550 sounds inferior to the power amp section of my three TA-8650's, even while being equipped as well with the ultimate V-FET rank 58. In schematics they are 99% identical regarding the power amp section, but they differ a lot in physical layout (internal wiring). Could this be the reason ? I don't know.

At the end everything is about taste. If you find transparent amps sounding boring, the TA-N7B is definitely not the best choice, so go for the rather warm TA-8XXX, B-1 or even the BA-1000 (if you ever find one).

If you are seeking for a rather neutrally sounding V-FET power amplifier, the 7Bs, B-3 , JM-S7 and even TA-5650 could be IMO the better choice.

If you are seeking for the best amp of the Seventies go directly for the N7(B) :D
 
roerdomp16e said:
I also know that the TA-N7 may need some care because of old age, but the 8550 works absolutely perfectly being even older.
Click to expand...

You should try to exchange all (!!!) the fusible resistors of your N7B (This is a problem, which plagues all Sony power amps between 1976 and 1986). The bipolar output transistors should be also changed and the replacements On Semi D44H and D45H series should be mounted with very low thermal resistance washers (e.g. Kapton) to the heat sinks. If you then adjust the bias current slightly above the value Sony recommends, you will probably not recognize the N7B again. You could also exchange the main capacitors, which is definitely not possible with the TAN-8550.

Btw.: If you don't like your N7B then, please send it to me, I have a use for it ... :D
 
mertol said:
I think I am one of the few people who own... even a ECR 500...
Click to expand...
There are several people on a couple of different forums at Head-Fi who'd love to have you show'n'tell your ECR-500.

Unda Maris said:
I own all the V-FET amps... and the BA-1000 (because of it's unique OTL tube like "hot rod" sound).
Click to expand...
Did you ever do a writeup of the BA-1000? It's a fascinating, mysterious amp.
 
I will write a review, but basicaly it's not on par with DT990 or Pioneer monitor on. did I mention that I aslo have a NOS Sony SB-5335, probably the rarest of all, could even be rarer than SS-8150 I guess.
 
mertol said:
I will write a review, but basicaly it's not on par with DT990 or Pioneer monitor on. did I mention that I aslo have a NOS Sony SB-5335, probably the rarest of all, could even be rarer than SS-8150 I guess.
Click to expand...

Some pics would be very nice............. :)
 
Cogsinister said:
Some pics would be very nice............. :)
Click to expand...

Indeed, if you have a SS-8150, it would be nice to also see it. Especially some close ups of the giant bass driver (go to the show us your Sonys thread).

SB-5535 is not so rare in Japan, you see it once a month on Yahoo.

Try this with a ECR-XXX ... ECR-880 :drool::drool::drool::drool::drool:

I still have to post some rare birds ... Stay tuned on the Sony thread
 
I am hunting for a SS-8150, but I am not sure that there is one in Turkey. I only have seen an 5150 so far. I agree that ECR's are also very rare, I got a ECR 500, but I dont think it's the rarest of all...

I will post some pictures as soon as I find my digital camera
Mertol
 
Unda Maris said:
You should try to exchange all (!!!) the fusible resistors of your N7B (This is a problem, which plagues all Sony power amps between 1976 and 1986). The bipolar output transistors should be also changed and the replacements On Semi D44H and D45H series should be mounted with very low thermal resistance washers (e.g. Kapton) to the heat sinks. If you then adjust the bias current slightly above the value Sony recommends, you will probably not recognize the N7B again. You could also exchange the main capacitors, which is definitely not possible with the TAN-8550.

Btw.: If you don't like your N7B then, please send it to me, I have a use for it ... :D
Click to expand...

Unda Maris, why the main capacitors of the 8550 can't be changed?
 
These capacitors are dual caps with three screw terminals (a big one of 2x10000uF as I remember and a smaller one for the pre sections).

Such caps aren't available anymore (much more rare than the V-FETs).
If one has to replace them, one has to find two caps e.g. 10000uF/80V, which fit into the space. Only low quality caps with a high CV product would properly fit in there, so the replacement will be definitely a bad (looking) compromise.
 
Doesn't exactly fit here, but as there's some talk about servicing these units..

I'm about to get my set of TAE-8450 and TAN-8550 completely looked through and would love to hear if there are some specialities that need attention for both units. The guy who's doing it is an engineer and also a hifi-nut, but has no experience with vfets.
I did a search on the vfets/diodes and ended with a whole of information, but nothing specifically for the TAN-8550. Could someone advice exactly what parts to exchange to what? I'm planning to keep these for a long time to come
 
Your best bet is to ask EW (Echowars, Glenn), and Unda Maris (Mirko)... those are the two guys that seem to know the most about VFET units.

Good luck! Will be great to know that, once the overhaul is done, you can now safely use your units for years to come :)
 
I still have to repair my TAN7B but my 8550 is working like a charm: the sound is sooo very very sweat: it is amazing. It is worth every penny.


I also have to get my 5550 working again. I expect that the 5550 is pretty close to the 8550 except for the power which you don't need 99.99999999% of the time if using these amps at home. When I first listened to 5550 I was just flabbergasted and started to listen to all my CDs all over again.

So my advise: get a very affordable 5550 and enjoy every minute and wait until you can get a 8550: the 5550 is in terms of design very similar as the 8550 which explains in my view the terrific sound of the 5550 with 4 fets per channel compared to the 6 V-Fets of the monster 8550. But I have to admit: I luuveee the optical VU meters on the 8550: they are one of a kind.

May be less is more?
 
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