Tube Amp matching to Speakers - better bigger bass from a smaller amp? Wha?!


#1

Sorry, this is not a PS Audio component question (I do own a Junior!).

So what happened?.. I purchased a new, smaller tube amp and now I have bigger / better bass. Same speakers.

I had a pair of monster VTL 300 deluxe, now a single, smaller PrimaLuna Dialog HP integrated… hmmmm…

My speakers are Focal Electra 1028 BE… specs below my signature.
My NEW amp (with bigger better bass) is a PrimaLuna Dialog HP Integrated (8 total KT88s) … specs below my signature
My prior amp (less bass) were monster high-power VTL Deluxe 300 monoblocks (16 total 6550s)… I don;t have the specs for these but they supposedly put out big, 300 watt power… don;t know the given impedance.

I am using the 4ohm taps on the PrimaLuna… IIRC, the VTL was optimized for 5ohms (?)

J Gordon Holt back in 1988 said these VTLs were some of the best sounding amps he heard. Now, my PrimaLunas sound more musical and have better bass. The PrimaLunas have a more “tube” sound… the VTLs did not have that tube sound per se, but were just wow and clear! until I put in the PrimaLuna… I love this PrimaLuna.

Peace
Bruce in Philly

Original J. Gordon Holt review of the VTL 300 Deluxe amps: https://www.stereophile.com/tubepoweramps/689/index.html

Focal speakers:


PrimaLuna with KT88s


#2

The fact that the VTLs are 30 years old might have something to do with it.
If you still have the VTLs, call them. Thet may be able to replace the caps and a few other components, making them much better. I just scanned the review, but it sounds like the VTLs have a lifetime warranty. Maybe they will bring it back to the original specs.
But it could just be that the new amp is a better design. 30 years ago,
bass in tube amps were not their strong suit.


#3

Thanx Jeff,

Good points… I actually soldered in a new cap pack VTL provided to me… I had to open them as the rocker switch actually arcs every time you turn them on… so darn much potential in there. The rockers are a wear item… Anywho, when I went to solder in the new rockers, I saw a few of the caps in there were swollen… so VTL sent me a back of caps… Ran fine for a few years, then one of the amps went silent… came back on, then would slowly go silent… I just gave up on them and sold them as is.

They were very transparent… finicky… chewed through tubes despite what the review said… and every 4-5 months, one would pop a fuse. I would burn my fingers biasing the darn things… I just gave up… time to move on… like dating a super model… at some point you just get sick of dealing with them.

I suppose I could have shipped them back to VTL… the shipping was stupid expensive, they weighed about 75 lbs each… had to go by truck. In the end, I figured it wasn’t worth it. VTL always charged me for parts.

I found an old pic of the VTLs when they powerd my Magnepan 20s. That beat-to-chit old industrial brick wall behind them was the best acoustical feature I ever had.

Peace
Bruce in Philly


#4

A lot has changed in tube (and solid state and digital and speaker etc.) design in 30 years! I know what you mean. I’m running a pair of 2.7 watt mono blocks now that are giving me all the sound I need and excellent frequency balance . … better than a 25 watt per channel amp I was using for six years very happily.

There are so many ways to get to great sound. . … we’re living in a wonderful time period.


#5

My guess is that your old amps are more accurate sounding.
The Prima Luna probably has less damping factor/ less feedback causing it to loose some control in the lower region. That is why you get more bass and a more tubelike sound. It has nothing to do with technology improvement. Tube technology was mature long before your old VTLs were made.
Nevertheless, accurate does not necessarily mean better in the wonderful world of hifi…
I have had tubes myself, not very accurate and totally unreliable but I loved the sound from the EL34 !
Enjoy your amp !


#6

Caliban: you may be on to something regarding the PrimaLuna’s lack of control… the bass I hear from it may not be accurate but I like it… maybe from owning my bassless Magnepans for so many years… I dunno, sometimes the bass from the PrimaLuna can be a bit tubby… but again, I like it.

Lonson/Caliban: I can’t say for sure what is different or what has improved in these amp designs over the years, but I know the VTLs were based on old AT&T/Bell Labs/WECO designs going back to the early 1900s. AT&T had to invent like… everything… back then. I read that tube amp designs over the years changed and improved to take advantage of improved and better tube designs but not because of new circuit inventions per se… but heck, I really don’t know. The VTLs look pretty darn simple inside that is for sure.

I miss them on cold winter nights… they could heat a home.

Peace
Bruce in Philly


#7

Peace Bruce. . . I bet they found a good home. I’ve been using Decware amps for 20 years and they do in my opinion represent some innovation in tube design, and sound fantastic. Glad you are digging the Prima Luna. . . being happy with a tube amp is a great thing. . . .