Shindo schematics?

[frankmalz]

Hi to all,

i am looking for Shindo 300B schematics.(Palmer etc.)

Has anybody a link or info about schematics.

Thank you very much

Frank

[ElectricHead]

What do you want with the schematics of such nasty sounding amps?

[frankmalz]

Hi,

the Palmer is a highly regarded amp and maybe there is something to learn about the use of a 6SN7 in combination with a 300B using NFB .

Best wishes

Frank

[ElectricHead]

Well, the 6SN7/300B combi is a very good thing, I 'm using monos with 6SN7/300B SE NFB (I have many power-amps).

We have to seperate here between audiophiles and vintage tube addicts. Mr. Shindo is not interested in the best possible sound, he is a religous fanatic using only horrible sounding outdated parts. The people who believe that Shindo sounds good are people who do not have the slightest clue about parts and how they alter the sound. I've used my own monos in a listening test against the Palmer and the owner of the Palmer told me that it was the most horrible sounding amp he ever bought. I had the feeling that it was completely undynamic, lifeless with extreme problems in the freq. extremes. No bass no body no textures - 2D sound stage. Looking at the parts Mr. Shindo used it is self explaining - I would use the parts in the Palmer not even in an old tube radio. But rip-off is normal in the Audiophile scene, and the people of the german hifi-press are industry-paid disgusting idiots who do not understand the SLIGHTEST thing about circuits and electronics...

Best regards
ElectricHead

[yagas]

So, you claim that all the above you describe about the Palmer's sound are a matter of "selecting components" ?

Mic

[ThorstenL]

Konnichiwa,

Originally posted by ElectricHead
Well, the 6SN7/300B combi is a very good thing,

Sorry, but that is not my experience. Usually you must plenty of parts that are distinctly non-neutral sounding to get anything approaching life or reality out of 6SN7 cascade 300B. I have herd them all, Reichert, JE, ANUK all the same stuff. Boring, congested and excessively euphonic, simply "pre-clear".

The Palmer was an exception, as it kills the charater of the 6SN7 by applying a good deal of negative feedback around the 2 6SN7 stages.

Shindo San's parts choices are controversial, agreed and they do not make for neutral sounding amplifiers, but that is not his point.

For Shindo gear I'd say around 50% of the sound is the parts used, another 30% are certain special tricks he applies (such as the feedback loop around the input/driver stage and the undersized output transformer in the Palmer, plus some I will not mention here), the remaining 20% are the schematic, hence having the schematic for Shindo gear is not particulary useful, without having the matching photos of the implementation too.

The sound of Shindo, it divides the spirits as they say, you either like it or not, few people can be anything except being polarised that way I noticed. I like Shindo Sound but in the long run it is a little too "chocolatey", for want of a better word.

Sayonara

[ElectricHead]

@Thorsten:

Well, you are right about the sound of the different implantation of the 6SN7. But please don't try to defend Mr.Shindo. I heard his completely unlistenable amp's espicially the Palmer. I'm tolerant to different tastes but a 300B amp without any bass or body (violins without wood) are not worth a discussion, not the mention the 2D stage like a cheap japanese transistor amp.

Without using Lundahl transformers, chokes & fast caps it is not possible to build a neutral and fast 300B amp, if you want to carry it further the speed and detail lane than one might also consider an EF86 instead of a 6SN7.

Looking at Shindo strictly scientifically it is a clear RIP-OFF period.

[ElectricHead]

Originally posted by Kuei Yang Wang


...hence having the schematic for Shindo gear is not particulary useful, without having the matching photos of the implementation too.

Sayonara

Yeah, that is right.

Good sound MUST have a material base, i.e.: An amp with mediocre parts can only sound mediocre, good parts don't mean automatically good sound. But without a kind of quality material standard you can't reach high levels of audiophilia.

[ThorstenL]

Konnichiwa,

Originally posted by ElectricHead
a 300B amp without any bass or body (violins without wood) are not worth a discussion, not the mention the 2D stage like a cheap japanese transistor amp.

I am not sure what you heard and where, in what system context, but this does not sound like anything I'm familair from the few pieces of Shindo gear I am familiar with.

Originally posted by ElectricHead
Without using Lundahl transformers, chokes & fast caps it is not possible to build a neutral and fast 300B amp,

Lundahl transformers are okay, far from the best though. Solen SCR "Fast Caps" have no place in quality audio gear, their tone is revolting, even black gate are preferable to these.

Originally posted by ElectricHead
if you want to carry it further the speed and detail lane than one might also consider an EF86 instead of a 6SN7.

EF86!!?? What for. Try an EL84 triode wired instead....Actually, you may wish to consider a design more like mine, if you want speed, detail, resolution, dynamics and a sound that is smooth, relaxed and makes you want to listen more:

http://www.jogis-roehrenbude.de/Lese...Loesch-Amp.htm

You might also check the recent D3a/300B DRD Amplifier thread for some ideas that I was able to input to Luis's design and realisation.

Key things to get a neutral sound from the 300B I found are:

No ECC99, 6SN7, 5687 et al cascade, absolutely NEVER EVER repeat the same valve twice in the driver stage.

Used as cascode this is another story, see penthode.

SRPP/Mu Follower et al is best avoided, it can do okay implemented with care, but usually it causes more problems than it solves.

Preferably ratchet up the Gm in the driver valve quite high and the anode impedance down, then SRPP et all are not needed, you have gain and drive readily available.

Never use more stages than absolutely needed.

Going 3-Stage (including powerstage) is okay if you use fairly powerfull low gain drivers (2A3, 45, 300B, 10, 205D, 6L6 et al) and low gain input valves, but most of the times 2 Stages (including powerstage) are preferable.

Example would be 6SN7 input and choke loaded 6BX7 driver, this is miles preferable to a resistor loaded 6SN7 cascade, but you start to cook seriously with a 417A or other highish Gm input valve and a 2A3 or KT66 as driver, IT/Choke loaded.

With Self Bias use the WE connection, if you don't you are missing the top 20...30% of the perfoirmance (dynamics, maturalism of sound) the Amplifier is capable of.

With fixed bias add a decoupled bypass to the last PSU capacitor.

The 300B requires DC Heaters (AC sounds foggy and indistinct - I need to try HF AC, that may be a happy middle) but these require utmost care in implementation in order not trade fog for severe glare and edginess.

Single stage pentode drivers (310A, EL84, C3m et al, the three mentioned I have build with) tend to have more delicacy and immediacy plus more than enough gain, tonal colours are rich and natural.

Triode drivers are a little more solid sounding and better on coarse dynamics, tonal colours are little bleached out.

Driver triodes need inductive or IT load = more delicacy, resistor load usually not recommended.

No Black Gates.

No PIO Coupling Capacitors.

No FastCap's.

If you can replace a resistor by a choke sensibly, do it.

Direct coupling usually swaps a good quality capacitor for a poor quality one, the results are unpredictable. If in doubt eliminate the cathode capacitor before a gridcoupling capacitor and remember, current flows in loops, if you do not give the signal current any other way to go the loop will complete through the Powersupply.

Output transformers with very high primary inductance for whatever resons do sound not right in the bass (and often equally crappy in the treble due to excessive leakage inductance), don't ask me why, but they don't (I suspect several things at work there, to early to talk much).

45's sound better than any 300B's, as do 10/10Y/VT25, if your speakers tolerate 1.5 - 2 Watt amplifiers.

Well, I'll add some if I remember any more.

Sayonara

[ElectricHead]

Jesus, quiet a lot of information from you.

1. I have a lot of schematics from you, I think you are very serious about sound quality so I really respect you.

2. Which transformers you consider better than Lundahl?

3. Black Gates are better than Solen? Oh come on.... please don't do that. The only problem the Solens have is the top... but there is a trick....