I love SET can we fix what I hate?

[DJNUBZ]

So I have owned a Decware Zen Select for years now. I love the little amp and I have yet to find another amp that comes close for the price. I am having an issue with tube gear, my own and other pieces I have heard. The bass is unacceptable when listening to modern music. I am increasingly finding all tube gear greatly lacking when it comes to listening to any current music that has serious bass. This includes amps and preamps connected to SS amps. Is this just the nature of the beast? Amazing midrange and treble at the cost of bass or is there something that can be done? Is this solely a function of the output transformer being deficient in some way? If you don't believe me take a listen to some Pendulum, Kruder & Dorfmiester or Ludacris.

This may just be a cranky rant. What I want it in a system is all the wonderful aspects of a SET amp but with accurate and powerful bass. Is that to much to ask?

[Jay]

Originally Posted by DJNUBZ

This may just be a cranky rant. What I want it in a system is all the wonderful aspects of a SET amp but with accurate and powerful bass. Is that to much to ask?

Depends on how much money you have.

Even for a subjectively expensive tube amp, the bass speed cannot satisfy everyone. You should have special speaker suitable for tube amps.

[DJNUBZ]

I do, I have the parker 98s but I have tried other speakers.

I should point out this is more of a frustrated vent then anything. Personally I think the fix is is a speaker that is efficient and has an active low end. Its just a shame there isn't some new technology that lets us have it all.

[century tek]

You just need to have the right combo. You are not going to get much of the eyeball rattling bass with something single ended anyway. My push/pull 30 watt mono wurlitzer tube amplifier shakes the house. I am using a single 15inch Magnavox woofer in an old cerwin-vega cabinet. Any music from rap to country, rock to jazz, sounds (and feels) awsome!

[Miles Prower]

Originally Posted by DJNUBZ

I am having an issue with tube gear, my own and other pieces I have heard. The bass is unacceptable when listening to modern music. I am increasingly finding all tube gear greatly lacking when it comes to listening to any current music that has serious bass. This includes amps and preamps connected to SS amps. Is this just the nature of the beast?

I don't have any problems with any lack of bass in my hollow state designs. These feature bass with "authority", none of that underdamped sloppiness, and accuracy such that quiet bass passages that simply aren't heard at all with most solid state amps become clearly audible. Like you, I listen to a lot of bass-heavy Techno. You don't need lotsawatts either, as the designs I've done so far come in at 30W and 40W.

To get good bass in any hollow state design requires, first and foremost, a good OPT. Cheap OPTs sacrifice the low end for smaller cores, cheaper lamms, less wire. In a lot of older designs, this was done deliberately to reduce hum. If your OPTs are smaller than your power xfmr, they're sonically inadequate.

Another problem was a lack of decent coupling capacitors. Back in "the day", there wasn't much besides wax paper capacitors and ceramics. While the paper capacitors packed a lot of uF's in small packages, they tended to leak (current, not oil or wax) and throw off the bias of the stages they coupled. Ceramics didn't have that particular problem, but didn't come in sizes that would make for good open loop performance at the low end.

You can have a frequency response as flat as a billiard table, but if it's NFB that's flattening the response, bass is likely to suffer. If the open loop frequency rolls off, so does the NFB, and the closed loop gain increases. Less NFB means less effective NFB that may not be damping the woofers adequately. These days, getting decent coupling capacitors -- like AuriCaps -- isn't difficult in sizes needed for good open loop performance. Of course, it helps to use DC coupling as much as possible. I do that as well.

[CLS]

Active xover with any amp(s) you like for the bass section.

[minhaj]

I think most important is right combination of amp and speaker.

Pls go make a pair of BiB with Fostex Fe206en it will shake your walls. Also Fostex Recommended cab for 208 sigma plays down to 30hz loudly.

If want to go extreme use a 20/25hz tapped horn with your fav speaker.

I request you to think out of the box (ss way) because tube is a voltage devise and operate differently than transistor. I personally suffered this dilemma when I migrated from ss many many moons ago.

Tube and SET is ok for deep bass no problem but it is different (and better) that SS bass. Condition for acheiving good bass from tube is 'FRESH THINKING.'

[DF96]

To get good bass you need either very big transformers or big transformers plus enough negative feedback. It can be difficult to add enough feedback to a SET amp as the open-loop distortion may be too high, so push-pull is better.

If you like SET for mids and highs, then maybe use SET for mids and highs and P-P for bass?

[kstagger]

I got good bass using an EL156 SEUL with a Hammond 1627SEA transformer. The 1627SEA is BIG and a little GNFB helped too. It's not quite in the same territory as my Threshold S/500 (which is in a class of it's own bass-wise), but with 15" woofers in my UREI 813As, there is some serious low-end content.

[danzup]

Originally Posted by minhaj

I think most important is right combination of amp and speaker.

Pls go make a pair of BiB with Fostex Fe206en it will shake your walls. Also Fostex Recommended cab for 208 sigma plays down to 30hz loudly.

If want to go extreme use a 20/25hz tapped horn with your fav speaker.

I request you to think out of the box (ss way) because tube is a voltage devise and operate differently than transistor. I personally suffered this dilemma when I migrated from ss many many moons ago.

Tube and SET is ok for deep bass no problem but it is different (and better) that SS bass. Condition for acheiving good bass from tube is 'FRESH THINKING.'

Fostex is a no go for real bass even in big horn man !!!

On the other hand all that response here give the solution : a lot of iron like my 25 square centimeters OPT i use in a PP amplifier (6P3S) with Triangle Alteea EX : bass like a Hurricane !