Your thoughts please - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 25th October 2002, 04:17 PM   #21
Ken L is offline Ken L  United States
diyAudio Member
 
Join Date: Sep 2002
Location: deep south
Default The subs are NHT1259 from Madisound

each with a KG5150

http://www.madisound.com/nht10subkit.html

I've got the schematics somewhere and was trying to find them for fdegrove - unable to do so in the confusion of the renovation -

I have been summing the subs together for LFE on Home theater and switching them to Left and Right to use as integrated active woofer for stereo -

The response curve rises too high around 120 or so - can't get to those notes either at the moment.

What to build?? I'm quite open to Fertins - and think they can probably be used with the horns I have on order -

While I missed the last Dixie Bottlehead listening session, due to work - I've been told the horns wowed the group - using dumpster diver drivers from a 1960's Philco open baffle stereo - They liked them better than the Sierra Brooks stuff and originally were bowled over with them in NY with Lowther PM5's as drivers.

So to sum up, you are pointing me more and more in the right direction, Planet 10 - I'm even seriously considering 2A3's as fdegrove suggested at one point - so it's hashing out nicely

Full range - lower power - elegant simplicity in circiutry - musicality with some dynamics and oomph - what circuits and tubes am I looking at?

uh-oh Real Life intrudes

Later

Ken L
__________________
No longer powered by Linux - not enough apps and cross platform integration - but maybe one day
  Reply With Quote
Old 25th October 2002, 07:57 PM   #22
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Default Re: The subs are NHT1259 from Madisound

Quote:
Originally posted by Ken L
Full range - lower power - elegant simplicity in circiutry - musicality with some dynamics and oomph - what circuits and tubes am I looking at?
It almost seems that the lower the power the better the potential of an amp. I'm pushing towards fully differential from TT thru to the speakers.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 25th October 2002, 08:12 PM   #23
Ken L is offline Ken L  United States
diyAudio Member
 
Join Date: Sep 2002
Location: deep south
Default I'm pushing towards fully differential from TT thru to the speakers.

What does that mean??

Fully differential from source to speakers??

Later

Ken L
__________________
No longer powered by Linux - not enough apps and cross platform integration - but maybe one day
  Reply With Quote
Old 25th October 2002, 08:19 PM   #24
Joel is offline Joel  United States
diyAudio Member
 
Joel's Avatar
 
Join Date: Oct 2002
Location: Brooklyn, NY
For what benefit, noise reduction? If you don't build noisy amplifiers, differential amps suddenly seem rather pointless.
  Reply With Quote
Old 25th October 2002, 08:53 PM   #25
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Quote:
Originally posted by Joel
For what benefit, noise reduction? If you don't build noisy amplifiers, differential amps suddenly seem rather pointless.
For the benefit of lower power I guess.
__________________
www.audiosector.com
Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it. - JC
  Reply With Quote
Old 26th October 2002, 07:38 AM   #26
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally posted by Peter Daniel
For the benefit of lower power I guess.
The speakers aren't really differential, but they will be bipoles. My source is primamrily TT, and the TT can be wired so that it is differential (some might use the term balanced). Then into a balanced differential preamp, into diff PP amps (no phase splitting required!) and then thru the OPT to the speakers.

Something like this:

Click the image to open in full size.

into something like this:

Click the image to open in full size.

If done as an integrated amp i figure the last stage of the preamp can disappear making things simpler and one less stage -- might even be able to lose both stages in the LL section (ie just put the output stage of the power amp where the "giant totem" cathode follower is). Of course things will get complicated a bit by the need to bi-amp.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 29th October 2002, 07:01 PM   #27
dice45 is offline dice45  Germany
diyAudio Member
 
Join Date: Jan 2002
Location: Munich, Bavaria
Ken,

crossreading the thread, i would say:
Keep the total system costs in mind, then the Fertins are no longer expensive.
Forget about a tweeter, you won't need one with the Fertin.
Drive the Fertins with a PP amp like Dave posted, using 45 as output tube and a decent OPT, Tango XE-45-8 for instance.
If you want to build the poser amp 3staged (as i do it), you even can tuck the eventual HP for the Fertin inbetween two amp stages and have the XO caps properly biased (as i do it).

This will not be cheap but it will be below what you end up with, building the Linkwitz setup at upper quality level.
And i respectfully doubt you will end up at the same detail resolution compared to the Linkwitz setup. Methinks the 45PP/Fertin setup will eat the Linkwitz setup raw from 100Hz upwards.

Correction concerning the 45: it has been hyped too long meanwhile $35 are asked for a decent used 45 and UX/globe goes >$100 if not >$200. . And you will have to buy some to find enough buddies: matching is a must with PP.

The Fertin seems to like PP better than SE IMO.

Subwoofer: if you give the Fertin/open baffle setup a chance, i sincerely recommend to go open baffle all the way. Why not use the Linkwitz woofer, it is reputed to have terrific sonics. Or you could do as i intend to do it: use a king-size open baffle and a pair of 18"ers per side.
In the meantime i have gotten my hands on a Russian tube amp delivering 60W and having fancy sonics in the low end. The "hospital-grade" Priboj amp (, referring to the ugly look, imagine a Soviet-Russian hospital). My buddy Peter Hartmann once re-built it completely, re-working the grounding scheme among other changes (non-starwired->starwired: dramatic improvement) and the owner (or hos wife?) got fed up with the optics. I am very curious if i will end up with the ASKA amp for the subwoofer or if the Russian beauty will make it.


Dave,

i liked Allen's power amp very much although i guess it was another version than the one you posted.
I once was intending to build Allens setup completely. His preamp i had several months for tryout. Did never warm my heart and on the long term i observed i was less and less listening to music.
Tryouts at Munich Triode Mafia meetings have shown the 85R of output impedance are phony. Into a resistive load: yes. Into a transformer: no. So why bother with this complex output circuitry, i asked myself. Allthemore as i did not particuarly like it, from the designer's conceptional POV. Too complex. And those 1F across the 2M2 (cathode follower tube) are in the signal!! They act as coupling caps, no matter what Allen says. His claim "the whole preamp has two coupling caps only in the signal path" i do not swallow.
Allthemore as he once pointed out how sonically important this cap is. He said, "you can vary the value but don't put junk in".


All,

This whole signal path talk is a gross simplification anyway. As long as we talk SE, the PS's last filter cap acts as coupling cap, undiluted, 100%, unless fancy stuff like choke-loading or CCS loads is used.
For a differential amp this is less and less valid the better the particular stage is balanced and the higher the CMPP and PSRR is. Nevertheless you hear any goof you make in the PS. So: everthing is in the signal and there is no signal path.

Joel,

my sonic experience with good differential tube amps is:
* better low end resolution
* blacker background/better downward dynamic range
* better tone colour distinctability
* tone colour saturation equal.
* sonic influence of PF diminshed.

Oh yes, and the interconnects pick up less hum. To me those advantages weigh enough to give a PP amp design using AD1 (ultra-rare German DHTs) a try. Let's not forget, one has to match tubes used in the same stage and better build matched quads to have both channels behave equal. For that a certain supply is needed unfortunaltely.
__________________
Greets,
Bernhard
  Reply With Quote
Old 29th October 2002, 08:26 PM   #28
Ken L is offline Ken L  United States
diyAudio Member
 
Join Date: Sep 2002
Location: deep south
Default Thanks everyone for your thoughts

You all have given me a good bit to think about.

I've got plenty of time to continue sorting things out on paper.

We've now moved a good bit of furniture into storage and we barely have space to live and eat - then in a week or so the kitchen is torn out - so it'll be a lot of eating out or cooked in a toaster oven.

thanks for helping me clairfy what I needed to be looking at

Sincerely

Ken L



BTW, I thought Tango was out of production - have they started back up - and/or do you know of a source
__________________
No longer powered by Linux - not enough apps and cross platform integration - but maybe one day
  Reply With Quote
Old 29th October 2002, 08:52 PM   #29
dice45 is offline dice45  Germany
diyAudio Member
 
Join Date: Jan 2002
Location: Munich, Bavaria
Ken,

Tango is back in business. Availability depends on the model. XE20-S, XE45-5 and XE45-8 are on the list. And some interstages too.

Another suggestion: if you stick to tubes with R_p of around 800R, 300B or 2A3 e.g, then Lundahl has one model having 5k:8R, the LL1663. Said to be a PP alternative to be taken serious at a fraction of the price.
Heck, one should ask Lundahl to make an 8k:8R version of it. But a minimum order of 25 pieces is needed for that.

I do the LL1663 <-> Tango XE45-5 comparison as soon as i have my amp running. Can take a while.
__________________
Greets,
Bernhard
  Reply With Quote
Old 30th October 2002, 05:46 AM   #30
diyAudio Member
 
jeff mai's Avatar
 
Join Date: Aug 2002
Location: Melbourne
Default Fully differential

Quote:
Originally posted by planet10


It almost seems that the lower the power the better the potential of an amp. I'm pushing towards fully differential from TT thru to the speakers.

dave
I had this idea once. It was put to me that it was necessary to have a single ended stage *somewhere* in the signal path. I can't remember the exact reason, but I think it had to do with imbalances produced by the phono cartridge. Was this bad information?

Jeff
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Any thoughts on this 108 cab? DaveCan Full Range 31 22nd May 2009 12:05 PM
813 Thoughts Steven-H Tubes / Valves 40 26th January 2008 02:24 AM
HT thoughts bjackson Multi-Way 5 8th February 2006 05:18 PM
Any thoughts on this Amp? ShinOBIWAN Solid State 8 3rd March 2005 01:43 AM
Some DAC thoughts Bernhard Digital Source 9 31st January 2005 02:54 PM


New To Site? Need Help?

All times are GMT. The time now is 03:35 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2