• 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

Scott 340B First Impression vs Fisher Receivers

sony6060

sony6060

Super Member
Banned
After a long sleep, the Scott 340B powered up perfectly and is fully functional.

Per my post yesterday I stated I will compare the factory stock Scott 340B to the factory stock Fisher receivers. The list of Fisher receives includes the models 400, 500B, 500C, 800B, TA-600 & TA-800.

Frankly, the Scott 340B sounds better in factory stock than the Fisher receivers with the exception of the TA-800. The two receivers are on par and strikingly sound about the same. Same 12AX7s, same family of phase inverters, power tubes operate close to the same operating voltages, etc.

The audio transformers are different. Although audio transformer tests show most of the Scott transformers superior to the Fisher 500C, no comparisons of the Fisher receiver audio transformers exist beyond the 500C. And, the Scott 340B TR-8-5-5 were not tested either. The other Fisher audio transformers are different than the 500C. After Fisher mods the 500C is not my top pick, but is the top pick in stock form for the smoother sound. I prefer 400 or B series after mods. The Scott audio transformers are likely class A rated with regard to overshoot and ringing as shown here- http://www.one-electron.com/trans_p1.pdf and here http://www.one-electron.com/trans_p4.pdf

The Scott 340B and TA-800 have superior treble and smoother midrange in factory stock condition. The Fisher midrange is not as affected by the bass control as much as the Scott. The Scott has a slightly more pronounced bass. The Fisher overall bass is a little better defined. Both were tested with Sylvania 7591 power tubes.

Surprisingly, switching tubes in the preamp and tone control sections from 12AX7s from Radio Shack & Raytheon to RCA 12AX7 black plate is not as pronounced in the Scott. I prefer the RCA 12AX7s in both receivers.

The Scott does have a better phono section as many have mentioned in stock form. But in stock form not as good as the Fisher with the Vit Q & K40Y-9 coupling capacitor upgrade. Dave's revised phono RIAA will bring the Fisher phono sections further up in performance.

The Scott 340B FM stereo tuner sounds good and is sensitive like the Fishers. I will measure the differences later. It does not sound quite as good as the Fisher FM tuners. However, this Scott 340B tuner seems to sound better then the Scott 350D tube tuner I owned if my memory of wanting better 10 years ago applies.

The Scott 340B has provisions for setting the tube bias with a digital meter and balance controls for each section. Nice touch.

I have to say out of the box and particularly without a budget to upgrade, the Scott is the better buy in stock form. The risk without upgrading is components failure such as a shorted power supply electrolytic capacitor.

Viewing prices, the two brands can sell for the same price, but the Scott is usually a little less expensive.

So, does the comparison make my right foot tap about replacing my Fisher 400? Errr.... No. The Fisher recievers does have this 'concert hall' sound I cannot describe beyond sounding musical, exciting and powerful and I am not making excuses for the Fishers- they just have it. But, the Scott is not upgraded yet. The 340B is better overall in stock form with the TA-800 out of the picture.
 
Last edited:
Register to hide this ad
That's great information Jim, looks like it might be a wash. But knowing the Scott can hang with the Fishers is a good thing.

I know that my TA-800 paired with my SL-1200, and Corwalls had even the "cool", curious, neighbors giving me the thumbs up last night. They are in awe of the old tube equipment, then you get the stories of how they threw out grampas tube stereo years ago. :sigh:
 
Interesting stuff Jim. Particularly that you mention the superiority of the mid-range and HF performance of the Scott. I believe this directly relates to the volume control at the input of the pentode input stage of the power amplifier section in the Scott design. With the volume control driving a pentode, there is no Miller at play in the Scott at normal volume settings, whereas there is in the Fisher, since the volume control -- at the same position in the circuit -- is driving the triode input stage in the power amplifier section in that design. As you know, that is one of the things I addressed in my 400 modifications.

Of course you as well as anyone know that there are others who say that pentodes in audio are the scourge of the earth....... It's not something I particularly buy into, although the small pentode tubes are generally more problematic than any 12AX7 tube will ever be over their lifetimes, which is a point to consider as well.

Miller is real, and your ears have likely detected it. Interesting stuff. Thanks for taking the time to post your findings!

Dave
 
I was very happy when I fired up my Scott after picking it up at a yard sale for 15 buck. It worked well right out of the box. I finally replaced parts as a precaution. The 340B is sensitive to which 6U8's are used. I eventually had mine aligned. the FM is very good.
 
This is in bone stock, all original form on the Scott, right? I'm just curious how it would fare with some fresh parts. I don't own Fisher or Scott gear, so no horse in this race but I just like to know stuff.
 
gadget73 said:
This is in bone stock, all original form on the Scott, right? I'm just curious how it would fare with some fresh parts. I don't own Fisher or Scott gear, so no horse in this race but I just like to know stuff.
Click to expand...

Oh, the Scott will get the same upgrades I place in the Fisher products.
 
sony6060 said:
Surprisingly, switching tubes in the preamp and tone control sections from 12AX7s from Radio Shack & Raytheon to RCA 12AX7 black plate is not as pronounced in the Scott. I prefer the RCA 12AX7s in both receivers.

The Scott does have a better phono section as many have mentioned in stock form. But in stock form not as good as the Fisher with the Vit Q & K40Y-9 coupling capacitor upgrade. Dave's revised phono RIAA will bring the Fisher phono sections further up in performance.
Click to expand...

My question would be: if the same upgrades were applied to the phono section of the Scott, would it outperform the Fisher, in that in stock form the Scott seems to sound superior to the Fisher phono section. I've read elsewhere where other people preferred the Scott phono section. Perhaps a clue lies in your comment about there not being as pronounced a change after tube rolling in the tone and input sections. I will be interested to hear your impressions after trying out those caps.
 
Last edited:
The Fisher units will typically be more sensitive to tube selection, which Sony has ably documented. That's because the Fisher phono preamp design uses two cascaded stages to supply the necessary gain, with NFB used to produce the RIAA EQ curve. However, at the low end of the audio spectrum, maximum gain is needed from the tube, and EQ feedback applied at these frequencies is greatly reduced. Therefore, slight variations in gain that can occur from tube to tube can affect the sound.

The HH Scott phono preamp design is identical in topology with one significant exception: The Scott design uses positive feedback between the cascaded stages to help enhance the open loop gain of the circuit. As a result, the equalizing negative feedback applied at the lower end of the audio spectrum is often more consistent from tube to tube with this approach, so tube rolling won't produce as great of an audible change.

Dave
 
Good Engineering Practice

As mentioned, careful selection of the 6U8 in the Scott 340B may improve the sound. A family of tubes that could be used in the 6U8 position are 6EA8, 6GH8 and 7643/E80CF.

The tubes do have different specifications with some having notably less gain at the triode section. I have been using lower gain 6BL8s vs 7199s in Fishers with a socket adapter. Sufficient gain was available from the 6BL8 triode section and the Amperex 6BL8 sounds better.

This Scott presently has GE 6U8s. I have just one Amperex 6GH8 and it sounds better already with that tube. I will try Amperex E80CF and Tung Sol 6U8 at the phase inverter. I know Tung Sol 6U8s sounds good in many circuits and the E80CF was recommended by others. I prefer to stay with the original design using 6U8s if the result is best sound.

I am not a proponent to just toss any tube in a socket and call it good. The engineers have designed circuits for certain tubes. In any industry to announce 'I found a miracle' with no back up support is reason to be shunned by the community itself.

Dave is disciplined as a professional engineer to explain with real world measurements his findings in the audio field. This is the sign of a properly disciplined engineer.

But, however 'sloppy' tube rolling is, if it sounds better, I'm in.

I will measure a 10kHz square wave with different tubes to perhaps find a pattern of why a certain tube sounds better. But, I doubt any significant findings will come forth.
 
Last edited:
I kind of suspect the only way you'll get any sort of measurement from tube rolling would be a full frequency response test and distortion measurement. That still may not actually say much of use, but it stands the best chance.
 
Hi Sony6060- Your findings pretty much correlate with what I've found for my Fisher 400 vs. Scott 340. The amp sections are very close. I prefer the Scott for vinyl and the Fisher for FM, but if I only had room for 1 receiver, I could be happy with either since the bandwidth of difference is very small.

From a DIY perspective, though, the Fisher is more desirable since they seemed to use better components and the chassis is more thoughtfully laid out for repair. The Scott multiplexer seems needlessly complicated compared to the Fisher unit.

From a cosmetics perspective, though, the all aluminum chassis of the Scott looks a lot nicer, and I love the metal knobs.
 

Attachments

  • DSCN9975.jpg
    DSCN9975.jpg
    80.4 KB · Views: 204
  • Fisher 400.jpg
    Fisher 400.jpg
    43.8 KB · Views: 178
Dadbar said:
Hi Sony6060- Your findings pretty much correlate with what I've found for my Fisher 400 vs. Scott 340. The amp sections are very close. I prefer the Scott for vinyl and the Fisher for FM, but if I only had room for 1 receiver, I could be happy with either since the bandwidth of difference is very small.

From a DIY perspective, though, the Fisher is more desirable since they seemed to use better components and the chassis is more thoughtfully laid out for repair. The Scott multiplexer seems needlessly complicated compared to the Fisher unit.

From a cosmetics perspective, though, the all aluminum chassis of the Scott looks a lot nicer, and I love the metal knobs.
Click to expand...


My personal perspective is I like the 400/500/800 Fisher dial best, Scott 340B front panel with all the pieces that fit together & best of both worlds- the Fisher TA-800 with a Scott like front panel and that Fisher glass. However, all are with a nice appearance.

I could not give up the Fisher FM tuner. The Fisher phono with upgrades including select tubes is better than the stock Scott. But, I have not upgraded the Scott phono yet.

If I had to have a Scott amplifier section it would be with a Fisher FM tuner as separates. Perhaps the early 299C amplifier with the larger audio transformers. I understand the later 299C and 299D had smaller audio transformers. Not much info is on the internet about this.
 
Sony -- If you think Fisher changed things mid production willy nilly, they were rank amateurs at it when it comes to Scott regarding this subject. Scott would change things at will, and give no thought about trying to document the change!

Dave
 
dcgillespie said:
Sony -- If you think Fisher changed things mid production willy nilly, they were rank amateurs at it when it comes to Scott regarding this subject. Scott would change things at will, and give no thought about trying to document the change!

Dave
Click to expand...

That is what I heard. Sherwood too.
 
I had hoped to hear your final comments on the Scott after all the mods, looks like you won't be able to share that with us Jim. :no:

I will most certainly miss my tube go to guy! :sigh:
 
Yeah, surprising and very, very-sad news... He has helped me more than any other AK'er... Without his advice and assistance, my hi-fi system wouldn't be what it is today. He easily saved me over $500 as well as an enormous amount of grief... I owe him big-time, and he's a big reason why I try to pay it forward with others by helping them with Wharfie stuff (since I am no Fisher expert).

So, if he happens to read this, let me just say that I am VERY-sorry to see him have to go, WHATEVER the situation... He's contributed SO-much here.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom