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Emperors new clothes and the sound of tubes

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Joel,
methinks you mix up some things here.
Joel said:
... There seems to be a general concensus on this forum about what is "good" design, and what isn't. About what "sounds good" and what doesn't. And there is an undertone of hostility towards those few members who do not think the same way. By posting comments saying that you don't believe in the different sounds of capacitors, you will get several condescending, or insulting posts hurled back at you. If you cannot quote from a "guru", you are labled un-informed. This is unfortunate.
i am not happy you see it that way. My claim: attitude forms reality and if you don't think you can hear any difference, you won't. Food for thought.

For the record, i have a buddy who is completely happy with his ECC83/ECC82-based RC-coupled preamp which indeed has an utterly seducing sound. He prefers it to the meaty Manfred Huber preamp. I do not but am happy to admit i like the unit's sonics in its way. And the unit is in complete contradiction to what i prefer for my circuits. I cannot speak for the others, but on my statements, please hang a big IMO, ok? :) I may sound different when i talk about design considerations, then i have a design goal i want to achieve, hence clear objectives. But i am happy to admit that there are devices in contradiction construction-wise to these
design goals and nevertheless sounding beautiful.
BTW, the guy did participate excessively in the tube rolling game until he arrived at a brand choice suiting him best. And is paying thru the nose for replacements now :)

I never said "all tubes sound the same". I am not an idiot. I know damn well that if you replace a 6SN7 with a 6SL7, it will work and sound differently. I never said SRPP is bad. I never said chokes or IT's are bad. Yet, some members feel obligated to insult me because I suggest alternate circuits.
I confess i said SRPP is bad for me. I do not like it. :)
The lack of openmindedness you imply is on both sides IMO, it looks as if you deny different tube brands to have any sonic influence, other members deny your circuit can sound good because it's too complex. No, i did not like how this was expressed (i admit, i too found it hard to swallow a 2stage lineamp worse, having paralelled tubes for output, is matching a lean mean single tube linestage).
But i haven't built your stage, it did not have any obvious design flaws and who am i to tell how it sounds then ...
I just jumped at your cathode follower remark and backupped with researched fact what your seemed to consider as urban legend.
What i can tell from own multiple experience: different tube brands have a small influence on sonics but nevertheless but not to be ignored, the simpler the circuit, the bigger the influence.
Admitted, circuit topology changes have a bigger influence. But **after** i got the circuit right, i a have no objection to play the tube rolling game. For my power amplifier, i did so already because i had to do a decision which brand to chase; i am intending to use a rare German DHT. Lucky me, for my ears the least fancy, the least famous brand sounded best. BTW the buddies joining this listening comparison and me were quite unanimous about which brand to prefer.

If you think gold foil capacitors with a linen dielectric made from mummy wrappings sounds better than anything else, fine. But don't attack me because I don't. This has become, sadly, a hobby about spending money, and following the latest dogma.:(
Hmmmh ... have my own dogma created here :D methinks MKVs sound best. They could be had at the diyAudio MKV group purchase,order list is closed now. This cap costs low compared to the gold/mummy-in-oil one but high compared to other industrial caps as it has unique techical features. Costing about $12 per piece. How much are Hovlands or Audionote copper/PIO? Well, according to listening comparisons i made, the MKV eats the Hovland and the Audionote raw sonically. According to measurements made the MKV wins hand down concerning tangens delta and dielectric absorption.
I did not follow any dogma, but i opened my mind to **possible** sonic differences between caps. And hadn't the differences been so huge and detailed, i would not have used that much time, in facts several weeks of my free time on that.
 
don't slam SRPP

First of all you guys have WAY too much time on your hands.
HA! Emperor has no clothes? All of your birthday suits are showing and it is not a pretty sight.

I have a FULL SRPP power amp! It has an input stage made up of 6av6 and a 6111 stacked on top of that. The output power tubes are SRPP 5998. This is by far a more authoritative sound than most amps out there. The only better thing than this is a big transmitter tube based unit such as SRPP 7403 or the like.

Take a look at the reviews of the VIPRE mic preamp. This is Mu-follower madness.

Stacked tube topologies have authority to there sound that is rarely matched, when done with the correct tubes.

Robert Morin
 
diyAudio Senior Member
Joined 2002
NOT AN INNUENDO.

Hi,

So what?

Set the casual apart from the exceptional?

There seems to be a general concensus on this forum about what is "good" design, and what isn't. About what "sounds good" and what doesn't. And there is an undertone of hostility towards those few members who do not think the same way.
By posting comments saying that you don't believe in the different sounds of capacitors, you will get several condescending, or insulting posts hurled back at you. If you cannot quote from a "guru", you are labled uninformed. This is unfortunate.
OTHO it does not imply differences between passive parts do NOT exist.
They do,and they're MAJOR to my ears.

First of all,lest you forget this is DIY.

No commercial constraints apply,you're free to do what you want and how you want to achieve your goal.

Relieved form all these commercial constraints we can then move on to build/roll our own.
You can construct/destroy all common sense and mix and toss to your hearts' content but physics still stand,no?

Knowing that we can then pick our building blocks,never to leave the house...

Remember,we're building for our own gear and nobody elses'.

Fine,we can now maximize potential.

Rule #1

Junk everything you suspect:

You start form the smaller signal and move up the chain;

What is there to cause a deleterious effect on the sound?

(for the record,I skip Ana (my dearest source of joy))

Assuming your CDP is Ok and has its' timing correct what can go wrong?

Once you adopt the RCA standard you loose already....

Preamp?

O.K.

You don't need gain,you know that don't you?

So what's going on?

Cables,that's what.
Stray capacitance,inductance,what have you.

We assume a perfect source for claritys' sake,good drive capabilties, low impedance and phase coherency.

Here,in the preamp we assume we don't want to alter the signal in any way we just want a modicus to change volume levels and drive the next stage in the best possible way.

O.K.,assuming no gain is required the best sollution for volume adjustment is a xfromer with multiple primaries and a low Zout.
Expensive stuff.
But it does the job and moreover it adapts itself to drive the next length of cable and input Z pretty well.

Can't afford it?

Think how much the next step down will cost you and you may as well save up.

Still.I'll present it:

At the input you'll have a constant impedance volume control driving a gridresistor + CF.
No not your ordinary CF,a special one with high current capabilties (for a tube that is) and low enough Z out to drive at least 10 M of ordinary cable (say an RG58) without any loss and frequency alteration.

Easy? Think again.

Does this come for free?

Nope,in order for the CF to work well it needs a very good PSU,preferably low Z and very,very well regulated.

Not to forget the CF will have an insertionloss as well.

Costly.

So,what to do?

Need gain?

No problem the same principles apply.

Gain means also phase inversion when taken from the anode of a tube and highish Z out.
No problem if you tack on a xformer.
Elegant solution if it weren't that in order to have high bandwidth
it is going to be expensive again.

No point in having a high bandwidth source to dump it into a filter right?

Well the good news is that with a bit of experimenting you can turn your ordinary xformer into an excellent one.
Provided you don't overdo things and stay within reasonable limits that 20Hz/KHz20 xformer can be made to sing well into 50KHz.
(not good enough for me but hey,I'm BATman)

Why's that?

Well,you're not sending too much power through it for a start and when you mix and match it a bit you can get away with it.

Am I defending Xformers here?

No,but let's face it, especially in the CD era they provide an awfull lot of benefits.

When talking all analogue I'd talk different for different reasons.

Are there other sollutions?

A ton of them.

Is this suggestion the best around?

In my DIY book yes,given this context.

Have I got a "cure all" for all kind of problems?

No way...

Cheers,;)
 
Re: don't slam SRPP

Robert Morin said:
I have a FULL SRPP power amp! It has an input stage made up of 6av6 and a 6111 stacked on top of that. The output power tubes are SRPP 5998. This is by far a more authoritative sound than most amps out there. The only better thing than this is a big transmitter tube based unit such as SRPP 7403 or the like.

I'd be interested in seeing a schematic if you can post it, or alternatively via email.

Cheers
 
frugal-phile™
Joined 2001
Paid Member
Re: Re: Re: don't slam SRPP

And here is Robert's amp for all:

dave
 

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Re: SRPP

fdegrove said:
Hi,

Robert,

I assume you lifted the heaters of the top half 6080 with respect to groung?

This sure looks like an interesting amp and reminds me of the Philips OTL.

Cheers,;)
I have all of the heaters running on one filament transformer. The 6as7 can take 300v plus or minus with respect to cathode. So a positive offset of 100v on the heater will keep the top 1/2 of the 6as7 happy along with the 6111.

Also an afterthought.
Either use a softstart B+ or don't power up the amp in a stand by mode ( use the filaments as a soft start) because the 6as7 will have a short life if B+ hits the tubes after filament warm-up.

Regards
Robert Morin
 
diyAudio Senior Member
Joined 2002
TRUE

Hi,

Also an afterthought.
Either use a softstart B+ or don't power up the amp in a stand by mode ( use the filaments as a soft start) because the 6as7 will have a short life if B+ hits the tubes after filament warm-up.

Actually that is valid for any tube,softstart is O.K but putting the out of standby does more damage than good.
Few people are aware of this.

I run monoblocks with 10 // 6AS7G that switched on directly.
It never caused any trouble since 15 years of use.

Cheers,;)
 
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