[TKonrad.NOLA]

I'm very close to purchasing a Primaluna Prologue 2 or Classic, but wondering if there are any alternatives.  I know about Jolida but I'm a little afraid to purchase their products with all the east vs west stuff going on with them. I'm also partial to Primaluna's adaptive autobias. 

Do all tube amps have point to point wiring and is it that big a deal?

[MaxCast]

With that kind of sensitivity we must ask how loud do you listen and are you seeking enough watts?

[SlushPuppy]

A couple of my friends have the Rogue Audio Cronos Magnum (90W) and love it.

[FullRangeMan]

Do all tube amps have point to point wiring and is it that big a deal?

There is a thread going on at Niteshade sub-forun, about Point-to-Point Wiring:
http://www.audiocircle.com/index.php?topic=98587.0
It does not need to be a genius to see that equipment that run hot, like tubed amps, can not use PCBs, except to keep the cost down and easy production.
Good Luck

[JohnR]

I wouldn't make generalizations. Isn't the Dynaco ST-70 the best-selling amp of all time? At any rate, a lot of them were sold. It has a circuit board - perhaps part of the reason for it's popularity and longevity - lots of people making replacement boards.

[tabrink]

Virtue M901 Sensation with Dodd tube buffer and Psvane tube!!
 


Best of luck in your quest!
Tom

[FullRangeMan]

I wouldn't make generalizations. Isn't the Dynaco ST-70 the best-selling amp of all time? At any rate, a lot of them were sold. It has a circuit board - perhaps part of the reason for it's popularity and longevity - lots of people making replacement boards.

OK, good post.   This is only my personal preference of course. Pardon.

[eclein]

+1 on the Virtue piece....I have a TWO.2 and it easily drove some 86db JBL  bookshelves I have since sold. Tremendous value!!

[rpf]

I just got my Rogue Cronus upgraded to Magnum status and also strongly recommend it. My speakers are 87 db efficient (8 ohm nominal, 4 ohm minimum) and 50-60 wpc tube amps (or 70-100 wpc SS amps) just weren't cutting it.

The Cronus Magnum puts out 90 wpc and I finally am hearing effortless dynamics. I don't listen particularly loudly either (very rarely above 85 db): it's about headroom.

Biasing is not automatic but is extremely easy with the built in meter and does not have to be done often. I've found it to stay steady for months.

There are plenty of amps with circuit boards from the '70s besides the Dynaco ST70 that are still functioning well. Also Rogue's service is superb.

[doug s.]

I'm very close to purchasing a Primaluna Prologue 2 or Classic, but wondering if there are any alternatives.  I know about Jolida but I'm a little afraid to purchase their products with all the east vs west stuff going on with them. I'm also partial to Primaluna's adaptive autobias. 

Do all tube amps have point to point wiring and is it that big a deal?

http://www.audiocircle.com/index.php?topic=98358.msg989677#msg989677
this amp is fixed bias, but all other things being equal, fixed bias amp will sound better than auto-bias.  and, it's easy to do, and it means you don't have to run matched tubes. and once the tubes are set, they only need to be checked every coupla months, and that's if you're obsessive... 

this amp has gotten good feedback from users when grant fidelity sold 'em at double the price.  true dual mono, and can be run as amp or integrated...

doug s.

[decal]

http://www.audiocircle.com/index.php?topic=98358.msg989677#msg989677
this amp is fixed bias, but all other things being equal, fixed bias amp will sound better than auto-bias.   

doug s.

Can you explain why, in laymans terms please?

[Ericus Rex]

Virtue M901 Sensation with Dodd tube buffer and Psvane tube!!
 

That's a hybrid right?  I took it that the op wanted all-tube.

The Rogue Cronus Magnum gets all the press these days, but I'd spring for the Rogue Tempest III that's listed here and on Audiogon instead.  It has all the features the Cronus has but more of what it sounds like you want; more punch, more headroom and more effortless sound for only a little more dough when buying used.  It comes standard as Magnum status and can be upgraded to Super Magnum if desired.

[doug s.]

Can you explain why, in laymans terms please?

here's a description, from a pro-audio site.  (realize that musicians may actually want more compression/distortion.)

http://www.vvtamps.com/support.htm :

"...What is Cathode bias (aka) Auto Bias versus fixed bias?

Cathode bias is an early method of biasing tubes where a resistor is placed in the cathode. Current draw through this resistor makes the grid potential negative with respect to the cathode. And, changes in tube conduction are automatically compensated by changes in bias so it’s also referred to Auto Bias. In Fixed Bias a negative voltage is applied directly to the grids of the output tubes. It should be noted that preamp tube are almost always cathode biased whereas output tubes may be either or both. Without getting into the technical issues of the difference between a fixed bias/cathode bias we will talk about the tonal qualities and how they differ in the real world.

The Pros and Cons.

Fixed Biased:
Fixed biased amps are more efficient, it is a brighter, tighter, punchier tone and needs to be pushed louder to find a warm sweet spot. Fixed bias also increases the headroom of the output section keeping the amp cleaner as it gets louder, yet the transition into grind is bit edgier. This design also requires you to bias the amp when replacing output tubes.
On the whole, most amps are fixed bias, your Blackface Fenders, Marshalls, and many of the newer amps such as Boogies etc.

Cathode biased:
Cathode biased amps have a slightly browner tone giving them a real warm appeal.
They also seem to have a rounder more full tone at lower volumes, and transition into grind smoother than a fixed biased amp. They also begin to compress sooner and have a more round, less focused low end, as well as a sweeter compressed, less edgy top end. They also have slightly less headroom.

Cathode biased amps don’t need to be re-biased when installing a fresh set of output tubes (but the set still needs to be matched). It is also a good idea to try and replace the output tubes with the same current draw as the originals. Most manufactures of tubes use a numbering system or color code to identify the tube’s draw. This keeps the tubes at the proper operating point....

here's a plug from primaluna (which the o.p. is considering); note that primaluna basically states what i said originally: "...For Tube-output stages the "fixed bias" system is most commonly used, because of its superiority in efficiency and least intrusion in the signal path. The most well-known other option is called "self-bias" or "cathode-bias", and this requires a big capacitor to bypass a big resistor, with the potential of affecting audio quality a lot more, and definitely burning a lot of wasted power in the already quite inefficient tube output stage....", but then goes on to explain why its system is better:
http://www.hifi-notes.com/primalunaprologueone24-en.htm

if you do a web search, you will find a lot of info on the differences...

doug s.

[brother love]

Virtue M901 Sensation with Dodd tube buffer and Psvane tube!!
 

I'll second that motion, BUT add the battery kit & charger.  .   Last I checked, Virtue Audio was having a 20% off sale as well. 

I have the Virtue Audio M-451 w/ tube buffer, Sonicap capacitor upgrades & battery kit.  Killer integrated amp in my 12' x 18' x 9' den, driving either some 85 dB eff. speakers I had prior or my current 91 dB speakers.

Edit: If interested in the Sensation integrated amp line, see http://www.audiocircle.com/index.php?topic=98321.0 for 20% discount code

[sonicboom]

Have to put a vote in for the Vista Audio i34.  Can't compare it to the Prima Luna, but to these ears at least, it betters the Jolida 502.  There are a couple of reviews out there on the Vista if you search for them. A couple or so years ago, there was one over at Affordable Audio and at the time I happened to agree on pretty much most points with the reviewer.  Good luck with your search.

[Quiet Earth]

   equipment that run hot, like tubed amps, can not use PCBs, except to keep the cost down and easy production.

I think that circuit boards can make production a little bit easier, but they are not always used just to keep the cost down. For example, some companies will use a circuit board to mount (hold) the parts in a specific place, and then they will use point to point wiring to connect those parts together. Then that circuit assembly is mounted into the amplifier case and wired to the rest of the parts. This technique might actually make for a more consistent product from the assembly line.

I just thought that I would mention this because I recently heard about a guy that freaked out when he opened up his amp and saw a circuit board inside.  It was later explained to him by the manufacturer that he did indeed have the point to point wiring that he paid for, and that he would be able to see that if he wanted to flip the circuit board upside down.

[FullRangeMan]

I think that circuit boards can make production a little bit easier, but they are not always used just to keep the cost down. For example, some companies will use a circuit board to mount (hold) the parts in a specific place, and then they will use point to point wiring to connect those parts together. Then that circuit assembly is mounted into the amplifier case and wired to the rest of the parts. This technique might actually make for a more consistent product from the assembly line.

Hi,
If you mean say a fiber glass board just to hold components, is it a interesting way of build a amp, I see it only in the expensive Joule-Electra OTLs, as pictured below.

Unfortunately all boards in a horizontal position blocks the flow of fresh air into the amp, and the components gets too hot in minutes, and over the months/years the board gets toast.
A pity, as the components resonance is low.  If a amp had a wiring too old, I can get a run of hard wiring on the nearest hardware store and put a new wiring/solder job myself, but with a PCB of any kind, I will get in the expensive hands of the equip manufacturer, Gulp!

I aware it is just my sole opinion, others are free to diverge, I may be a picky guy.
Regards

[Quiet Earth]

Yes, a circuit board without any traces, or a fiberglass board just to hold the components, as you put it. I do understand your concern for heat though, and it is something that I am always concerned with too. But I don't know if it is fair to say :

all boards in a horizontal position blocks the flow of fresh air into the amp, and the components gets too hot in minutes, and over the months/years the board gets toast.

I don't think that it would be fair to say that all boards are doomed for failure because not everyone uses a board that spans the entire area of the case like the picture that you provided. And there are usually plenty of air vents on the bottom. I usually see much smaller subassembly boards placed inside of a case with plenty of space around it/them. I do share your concern for heat though, because I know what heat damage can do. But we have to look at reality too. For example, my amplifiers have small subassembly boards inside, they are over 6 years old, and they get used almost every day. They run in class A so the parts inside are getting a work out. They (the boards) have not burned up yet (knock on wood! ). Same goes for the DAC and phono stage. So while I am as concerned about it as you are, I have to look at the history of usage, just like John mentioned earlier.

I'm not trying to pick on you either.  I totally respect your opinion!

I'll just order the Primaluna

I guess we got a little off topic.  Sorry 'bout that DigitalDude. Good luck with your Primaluna, I hope it is everything that you are hoping it will be!

[Diamond Dog]

This would be fun but it might be a little light on power for those speakers of yours...




D.D.

[FullRangeMan]

QuietEarth:
Thanks for your kind words,
I fell small pre-amps tubes will not cook the PCB, as the heat seems to be small.
And the 2A3 (cathode is onli 2,5V) and 300B(cathode is 5V) seems to made small heat, but I can be wrong, as I never owned this tubes amps.

So, Iam refering to more powerfull tubes, as Pentodes(6550, KTs etc), 6C33 and big triodes.
Of course if a amp had four 300B or EL34 etc the situation can be hot in the summer.
I must confess I listen the BAT VK75SE(which is a full PCB amp) and the sound is good.
Cheers