Jonas Hellborg Warwick arrives!

[JimmyM]

Well, in other forums, people commonly discuss which transistors sound best also. And people buy up 40-year-old diodes and transistors just like people buy 40-year-old tubes. Personally, I think the variance in tubes is overstated.

Besides that, it was my understanding that the Hellborg amps were in fact going for a "tube sound", by using an output transformer, which you would normally only see in a tube amp, and which some people believe has a lot to do with the "tube sound", whatever that means.

Correct. Jonas believes the OT is 100% responsible for tubey tone, and says that tubes should have no sound coloration on their own. Whether I believe that or not, I don't know since I never played a SS amp with a tube amp's giant OT.

And ignore Seamonkey. His purpose in life seems to be coming into threads where people talk about tubes and saying they suck.

 

[seamonkey]

Well, in other forums, people commonly discuss which transistors sound best also. And people buy up 40-year-old diodes and transistors just like people buy 40-year-old tubes. Personally, I think the variance in tubes is overstated.

Besides that, it was my understanding that the Hellborg amps were in fact going for a "tube sound", by using an output transformer, which you would normally only see in a tube amp, and which some people believe has a lot to do with the "tube sound", whatever that means.

I haven't seen these discussion, it must be rare compared to the tube ones. I have seen large reviews of op-amps where they spend a lot of time talking on details that a human being couldn't hear.

In my opinions, in the Hellborg, since the output transformer is not doing any transforming (high-voltage+low-current to low-voltage+high-current) it's adding "resistance" to the circuit, the same as adding a resistor to the output and thus making the frequency response tend to follow that of the driver impedance. Which happens to resemble a smily face EQ that most people find appealing.

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"This effect is caused by the resistive speaker impedance and the output imedpance of the amplifiers. The transistor amp has an output impedance of less than a tenth of an ohm, whereas the tube amp has an output impedance of above five ohms. Thus the output of the tube amp will increase as the speaker impedance increases."

 

[fdeck]

"This effect is caused by the resistive speaker impedance and the output imedpance of the amplifiers. The transistor amp has an output impedance of less than a tenth of an ohm, whereas the tube amp has an output impedance of above five ohms. Thus the output of the tube amp will increase as the speaker impedance increases."

Tube power amps used for bass amplification tend to employ negative feedback that greatly reduces the output impedance. Thus the above statement is inapplicable to the subject being discussed.

 

[JimmyM]

Tube power amps used for bass amplification tend to employ negative feedback that greatly reduces the output impedance. Thus the above statement is inapplicable to the subject being discussed.

Seems to be a lot of that in seamonkey's posts

 

[seamonkey]

Tube power amps used for bass amplification tend to employ negative feedback that greatly reduces the output impedance. Thus the above statement is inapplicable to the subject being discussed.

Tubes have nowhere near the gain of SS and thus cannot provide the full negative feedback to counteract the resistance (Thevinin) in the whole amp. There's resistors all over power supplies in these amps.
You would not be able to create a modern op-amp using tubes, there is not enough gain.

Of all the schematics I've seen posted, A tube amplifier feedback is from a separate winding, not from the actual speaker out. And it's up to the amp maker how much they apply feedback.

We do not know what the feedback path is for the "Hellborg". If by listening the only applied it before the output transformer and heard what they considered "tube sound" then they are getting extra resistance outside the feedback loop. To their ears - this sounds like tubes. It's their artistic interpretation.

 

[seamonkey]

Seems to be a lot of that in seamonkey's posts

You've already proved through listening tests people can't hear a difference between SS and tube.
Why do you feel you need to follow me around and troll my posts? You must be sensitive to your own contradictions.

 

[fdeck]

Tubes have nowhere near the gain of SS and thus cannot provide the full negative feedback to counteract the resistance (Thevinin) in the whole amp. There's resistors all over power supplies in these amps.
You would not be able to create a modern op-amp using tubes, there is not enough gain.

Of all the schematics I've seen posted, A tube amplifier feedback is from a separate winding, not from the actual speaker out. And it's up to the amp maker how much they apply feedback.

SVT uses the same winding as the speaker out. Maybe you know a counterexample from a contemporary tube bass amp?

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I only have one reference to a tube amp with schematic and published damping factor, but the DF is given as 40:1 for a relatively simplistic circuit.

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We do not know what the feedback path is for the "Hellborg". If by listening the only applied it before the output transformer and heard what they considered "tube sound" then they are getting extra resistance outside the feedback loop. To their ears - this sounds like tubes. It's their artistic interpretation.

Or their marketing interpretation. I am making no claims about "tube sound."

 

[seamonkey]

SVT uses the same winding as the speaker out. Maybe you know a counterexample from a contemporary tube bass amp?

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I only have one reference to a tube amp with schematic and published damping factor, but the DF is given as 40:1 for a relatively simplistic circuit.

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There are other amps with separate feedback windings. for example:
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40:1 - sure but damping factor varies with frequency. One of the first calculations I've seen done when designing a transformer is to spec out frequency response, which includes the lowest frequency to be passed. No low frequency passed means no feedback, an thus lower damping at low frequencies. And as you know the speaker itself impedance varies with frequency. These work together, so there is some balancing but there is still resistance in the wires when the feedback cut outs.

I have the chart from the Milbert article, but you just don't see amp manufacturers of tube amps publishing them into speaker loads. When asked, I have received replies that those measurements are "proprietary".

 

[fdeck]

Why don't you measure it? Otherwise it's all idle speculation.

 

[JimmyM]

You've already proved through listening tests people can't hear a difference between SS and tube.
Why do you feel you need to follow me around and troll my posts? You must be sensitive to your own contradictions.

Not really. I proved that two exceptional SS products out there could make people think they used tubes. Two products out of thousands. That's not exactly a mandate.

 

[sandman]

to me....the hellborg, and possibly other neve type jobbys, sounded the way people talk about tube sound, as in having a round kind of envelope to the sound, and i;m talking about the preamp only.
As far as the power amp, i do think it sounds better than my cheap crown.

I have nothing to add to the details of engineering being discussed....
There's a sound clip in the link in my sig, of the hellborg pre straight to desk recorded NYE 07, i think the mixer added extra boom to the bass sound during mixing, that i don't recall hearing on stage. - go to media page.
(bass is a warwick streamer stage 2, in case you want to know)
cheers, Sandy.


i may have posted this already...

 

[markorbit]

There's a sound clip in the link in my sig, of the hellborg pre straight to desk recorded NYE 07, i think the mixer added extra boom to the bass sound during mixing, that i don't recall hearing on stage. - go to media page.
(bass is a warwick streamer stage 2, in case you want to know)
cheers, Sandy.
i may have posted this already...

Nice big fat warm sound and articulate when it needs to be. I like it.

 

[chadds]

to me....the hellborg, and possibly other neve type jobbys, sounded the way people talk about tube sound, as in having a round kind of envelope to the sound, and i;m talking about the preamp only.
As far as the power amp, i do think it sounds better than my cheap crown.

I have nothing to add to the details of engineering being discussed....
There's a sound clip in the link in my sig, of the hellborg pre straight to desk recorded NYE 07, i think the mixer added extra boom to the bass sound during mixing, that i don't recall hearing on stage. - go to media page.
(bass is a warwick streamer stage 2, in case you want to know)
cheers, Sandy.

i may have posted this already...

There's humor going around how to identify something as "better than" you put Neve on it. Neve Shalom for a synagogue and Neve Campbell...well that speaks for itself doesn't it?

It seems that some of what we are hearing is analog not tube. Except for compressors of the old days these recording desks didn't have tubes. Unless you mean those from '50s.
I find that my basses sound warm and "tubish" so I often prefer clear accurate reproduction. I started playing when all we had were these much sought after B-15s, SVTs, Sunns, Fender, Marshalls, Hiwatts etc. I know. I used to play an old Altec tube pre and power amp into an Ampeg 8x10 as late as 1979. In the old days SS sounded like POOO. Then it got good. The lines are blurring.

 

[fdeck]

There are different levels of Neve design:

Designed by Rupert Neve: The pinnacle, it means that the circuit was designed by the great man himself.

Based on a Neve design: Lots of coils and transformers.

Inspired by Neve designs: The endorser fondly remembers Neve consoles.

Influenced by Neve designs: We once looked up some Neve schematics online.

 

[BassmanPaul]

the wonders of pricing of same products in different markets never seize....

here current local (German) prices of preamps
(incl. 19% local tax, so for export "x0,81", excl. shipping)

Hellborg Pre - EUR 1.449
Markbass Studio Pre - EUR 1.449
Glockenklang Pre - EUR 1.049
Eden WT 100 - EUR 999
Alembic FX-1 /F2B - EUR 999
SWR MM - EUR 838
Fender TBP1 - EUR 749


for a further bit of context:
Neve Portico 5033 - EUR 1.489
UA LA 610 - EUR 1.499
Avalon VT 737 - EUR 1.989
Millennia Stt1 - 2.490


So is the Hellborg Pre -
overpriced ? at least here, no, in line with other boutique pre's
expensive ? depends on what you compare to....
worth it ? Not to me... YMMV

My question is: how many audience members were able to say that the bass sounded sooo much better that it did last time you played? Or did ANYONE even notice or care even if they did? Myself, I question if my old abused ear holes could really tell much of a difference. Yes we all strive for that tone that we hear in our heads but is a unit costing more than three grand going to get closer that a well designed pre at a quarter of the price.

When I first saw the ad for the Hellborg amp I fell in love with the looks. However I thought that the pre was the whole amp and that it was a one space "digital" amp. When I got the whole picture I lost interest. I really don't feel like toting an amp around that weighs more than my speakers. That's the reason I don't use tube amps anymore. <sigh> I must be gettin' old!

Paul

 

[chadds]

There are different levels of Neve design:

Designed by Rupert Neve: The pinnacle, it means that the circuit was designed by the great man himself.

Based on a Neve design: Lots of coils and transformers.

Inspired by Neve designs: The endorser fondly remembers Neve consoles.

Influenced by Neve designs: We once looked up some Neve schematics online.

lol

 

[BassmanPaul]

Of all the schematics I've seen posted, A tube amplifier feedback is from a separate winding, not from the actual speaker out.

I have to disagree with this statement Seamonkey. The only amps that immediately come to my mind that use this feedback connection are the MacIntosh amps. Every other tube amp that I can think of takes it's feedback loop from the secondary feeding the speakers.

Paul

 

[seamonkey]

Why don't you measure it? Otherwise it's all idle speculation.

This paper measured it and did a blind test.
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No one would believe any new measurements.

BTW - love the SVT schematic with the clipping diodes. Before someone says there are there for protection. They breakover at .7v - that's not much, power amps usually can handle more.

 

[seamonkey]

I have to disagree with this statement Seamonkey. The only amps that immediately come to my mind that use this feedback connection are the MacIntosh amps. Every other tube amp that I can think of takes it's feedback loop from the secondary feeding the speakers.

Paul

OK.
Still there are multiple taps, so the feedback may not be directly on the tap the speaker(s) are connected to.

MacIntosh seems to be the ultimate standard people think of when they think of clean tube power. Maybe separate feedback windings is what it takes?

We still don't know what Hellborg does, or if it has any feedback past the transformer. If it doesn't, then it's using the Carver effect.

 

[seamonkey]

to me....the hellborg, and possibly other neve type jobbys, sounded the way people talk about tube sound, as in having a round kind of envelope to the sound, and i;m talking about the preamp only.
As far as the power amp, i do think it sounds better than my cheap crown.

I have nothing to add to the details of engineering being discussed....
There's a sound clip in the link in my sig, of the hellborg pre straight to desk recorded NYE 07, i think the mixer added extra boom to the bass sound during mixing, that i don't recall hearing on stage. - go to media page.
(bass is a warwick streamer stage 2, in case you want to know)
cheers, Sandy.


i may have posted this already...

You bring up a good point.

If you're hearing what you consider tube sound straight from the preamp, it may be designed to do all the work and the transformer is just a white box gimmick in the Hellborg.