Welcome, Guest. Please Login or Register
Decware Audio Forums
03/29/24 at 00:37:25 




Pages: 1
Send Topic Print
SE84 clone headhone amp (Read 2461 times)
funch
Seasoned Member
****




Posts: 151
SE84 clone headhone amp
03/01/21 at 22:50:24
 
My amp is a duplicate of an SE84 but using Transcendar headphone output trannies. I've learned a lot with this build, especially how different rectifier tubes have different voltage output, which may account for the differences in their sound.

I still have to install the anniversary mod's and try to remove a low-level hum, but it sounds fabulous.




Back to top
 
 
  IP Logged
piezoman
Ex Member



Re: SE84 clone headhone amp
Reply #1 - 03/02/21 at 16:51:56
 
wow, that is fantastic!
Back to top
 
 
  IP Logged
DPC
Ex Member



Re: SE84 clone headhone amp
Reply #2 - 03/02/21 at 17:29:54
 
+1  :o
Back to top
 
 
  IP Logged
Brian
Seasoned Member
****




Posts: 897
Re: SE84 clone headhone amp
Reply #3 - 04/01/21 at 03:27:57
 
A wonderful thing to build!
Have you any thoughts on the cause of the hum?

Brian
Back to top
 
 
  IP Logged
funch
Seasoned Member
****




Posts: 151
Re: SE84 clone headhone amp
Reply #4 - 04/02/21 at 23:23:12
 
Thanks. Yes I did solve it just a couple of days ago. The problem was the power supply. I installed a 15H/75 mA choke between the filter capacitors.  I also installed a 250 ohm/5W resistor in series with the choke to get the B+ power to the correct voltage. Both of these items replace the 1k ohm/5W resistor that is in the stock amp.

As designed, the power supply filtering in the stock SE84UFO is perfectly adequate for its intended use; speakers. It does hum, but you only hear it if you put your ear up close to the speakers. Not exactly a normal listening position, unless you're weird, or have a very small room. Wink
I had a Taboo II amp a few years ago which, I believe, was the first amp Decware put a headphone jack on, and it had a choke in the power supply.

With headphones though it is quite apparent/annoying. Installing the choke smooths out the waveform B+. Now, using the low impedance output (35-300 ohms), the amp is dead quiet. The high impedance output (300-600 ohms) has an almost imperceptible hum, which is masked if a gnat farts from across the room. I use Sennheiser HD800's btw (300 ohms), from the low imp jack.

With 2.3 watts output, I can only run the volume knob at or below 9 o'clock without going deaf. I can't wait to try a nice pair of planar headphones with it.

With the headphone specific output transformers, this amp is amazing. Very dynamic, but also smooth, with a great soundstage. Personally, I think this is the headphone amp Decware should build. But, that's my humble opinion. :-0

Back to top
 
 
  IP Logged
Brian
Seasoned Member
****




Posts: 897
Re: SE84 clone headhone amp
Reply #5 - 04/05/21 at 05:29:03
 
This is fantastic!  It is so much fun to get beautiful sound.  And to accomplish it with your own building adds to the enjoyment.  
I am happy for you.

Brian
Back to top
 
 
  IP Logged
funch
Seasoned Member
****




Posts: 151
Re: SE84 clone headhone amp
Reply #6 - 04/19/21 at 03:04:24
 
I have a question about plate voltage on the SV83 tube. Depending on the rectifier I'm using, I measure anywhere from 300 to 338 volts at the plate.
The SV83 datasheet (Svetlana) lists 300 as the maximum plate voltage.
Am I going to ruin my 83's by running over 300 volts?
Back to top
 
 
  IP Logged
funch
Seasoned Member
****




Posts: 151
Re: SE84 clone headhone amp
Reply #7 - 05/01/21 at 05:06:10
 
Final configuration. Probably.

Back to top
 
 
  IP Logged
funch
Seasoned Member
****




Posts: 151
Re: SE84 clone headhone amp
Reply #8 - 05/18/21 at 02:14:46
 
Being a charter member of the 'Don't-know-when-to-leave-well-enough-alone' club, I of course had to tweak things a bit. (Won't bore you with the details). All of the silver stuff is Dynamat to dampen the enclosure and some of the capacitors.



This amp continues to amaze (no, that word is too weak). Maybe stupefy is better. The only other amp I've heard that gives a similar sound is the Eddie Current Balancing Act, which I owned at one time, and cost more than three times what it cost me to build this. You name a trait (soundstage, impact, separation, detail, yada yada, and this amp has it in spades. 'Nuff said.
Back to top
 
 
  IP Logged
GroovySauce
Seasoned Member
****




Posts: 784
Re: SE84 clone headhone amp
Reply #9 - 05/18/21 at 16:14:51
 
What differences did you notice to adding dampening to the chassis? I was thinking about dampening the chassis of my amps. I am concerned about any negatives.

Your build looks really clean, well done!
Back to top
 
 

Maximus NEO TT|ViV Rigid Float TA | Phasemation PP-200 or Hana ML | Sutherland Little Loco MK2 | Innuos ZENith MK3 | LampizatOr GA TRP | EMIA Remote Autoformer | Add-Powr Sorcer x4 | Snake River Audio Cables | PAP Quintet 15 1.6 Voxativ |Torus AVR15|AF Treatment
  IP Logged
funch
Seasoned Member
****




Posts: 151
Re: SE84 clone headhone amp
Reply #10 - 05/19/21 at 02:23:29
 
Thanks. Mostly I dampened the chassis (the bottom is also damped) because the Hammond enclosures are about half as thick as the stock SE84, and I don't think you can have enough 'deadness'. The Miflex coupling cap's really need it because the way they're mounted, if I tapped one, it would vibrate, and that can't be good. The PS bypass cap's also, but to a lesser extent.

Sound wise, maybe a tad more focused, but that might also be me faking myself out.



Back to top
 
 
  IP Logged
GroovySauce
Seasoned Member
****




Posts: 784
Re: SE84 clone headhone amp
Reply #11 - 05/19/21 at 13:20:44
 
For dampening I'm still experimenting. I have found consistent improvement with tube dampers. I've found mass loading components to also have a positive impact. opening the chassis to add some sticky dampening material I'm still hesitant about.
Back to top
 
 

Maximus NEO TT|ViV Rigid Float TA | Phasemation PP-200 or Hana ML | Sutherland Little Loco MK2 | Innuos ZENith MK3 | LampizatOr GA TRP | EMIA Remote Autoformer | Add-Powr Sorcer x4 | Snake River Audio Cables | PAP Quintet 15 1.6 Voxativ |Torus AVR15|AF Treatment
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. Dick

Posts: 23310
Re: SE84 clone headhone amp
Reply #12 - 05/19/21 at 13:36:32
 
You can damp a component or tube etc. but dampening it. . .not recommended! Smiley
Back to top
 
 

HR-1,ZTPRE,ZBIT,ZROCK2,SEWE300B,CSP3-25mod,Taboo MkIV;Rega RP3 all GrooveTracer mods;PSAudio:PST+DSD,P15,NPC,PowerBases,AC-12 pwr cbls,Reference spkrcbls;Mapleshade SamsonV3;VooDoo:Cremona+Amati interconnects, IsoPods; headphones:Sennheiser HD800S,ZMF Ori,Oppo PM1
  IP Logged
HockessinKid
Seasoned Member
****




Posts: 1084
Re: SE84 clone headhone amp
Reply #13 - 05/19/21 at 14:01:38
 
Personally I'm with Lon, dampening a chassis particularly one of Steve's amps or preamps just doesn't make any sense. There may be some benefit to tube dampers if you have ones that exhibit microphonics.

With that said I did find some benefit to dampening flimsy, inexpensive CD players years ago. Keep in mind these mass produced machines exhibit a lot of vibrational energy and dampening in this situation can help. No such problem with my Audiolab 6000 CDT. This thing is rock solid.

HK
Back to top
 
 

Nottingham Interspace TT w/ Audio Technica AT-OC9XML cart + Modwright PH 9.0XT phono OR Modwright modded Cambridge CNX V2 > CSP3-25th Ann. preamp > ZMA-25th Ann. amp > PI Audio UberBUSS > Caintuck Audio Lii15 Magnum speakers > Snake River Audio & ZenWave cables
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. Dick

Posts: 23310
Re: SE84 clone headhone amp
Reply #14 - 05/19/21 at 15:39:50
 
Ha, HK I don't necessarily disagree about the chassis, well I do . . . I find benefit sometimes on some chassises. But my point was one can "damp" of do "damping" for vibration and isolation. . . but to "dampen" or do "dampening" is to make things WET. Wink
Back to top
 
 

HR-1,ZTPRE,ZBIT,ZROCK2,SEWE300B,CSP3-25mod,Taboo MkIV;Rega RP3 all GrooveTracer mods;PSAudio:PST+DSD,P15,NPC,PowerBases,AC-12 pwr cbls,Reference spkrcbls;Mapleshade SamsonV3;VooDoo:Cremona+Amati interconnects, IsoPods; headphones:Sennheiser HD800S,ZMF Ori,Oppo PM1
  IP Logged
Archie
Seasoned Member
****




Posts: 2731
Re: SE84 clone headhone amp
Reply #15 - 05/19/21 at 16:37:37
 
These replies caught me off guard before I realized the tongue in cheek part.

To be clear, damping (or isolating) components from vibration is generally good and "dampen" also means "to deaden, depress or reduce."   Wink
Back to top
 
 

ZLC
Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
GroovySauce
Seasoned Member
****




Posts: 784
Re: SE84 clone headhone amp
Reply #16 - 05/19/21 at 16:47:55
 
I read Lons comment as a joke. Cheesy I did go and double check the dictionary though lol.

HK, What is your thought process on why it doesn't make any sense? Using anti vibration footers sometimes makes an improvement. Mass loading components sometimes is another improvement. I figure dampening the chassis might be another area of improvement.
Back to top
 
 

Maximus NEO TT|ViV Rigid Float TA | Phasemation PP-200 or Hana ML | Sutherland Little Loco MK2 | Innuos ZENith MK3 | LampizatOr GA TRP | EMIA Remote Autoformer | Add-Powr Sorcer x4 | Snake River Audio Cables | PAP Quintet 15 1.6 Voxativ |Torus AVR15|AF Treatment
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. Dick

Posts: 23310
Re: SE84 clone headhone amp
Reply #17 - 05/19/21 at 16:49:22
 
Ha! Yes, it does also mean that. Neither of these definitions represent something that is good in audio!
Back to top
 
 

HR-1,ZTPRE,ZBIT,ZROCK2,SEWE300B,CSP3-25mod,Taboo MkIV;Rega RP3 all GrooveTracer mods;PSAudio:PST+DSD,P15,NPC,PowerBases,AC-12 pwr cbls,Reference spkrcbls;Mapleshade SamsonV3;VooDoo:Cremona+Amati interconnects, IsoPods; headphones:Sennheiser HD800S,ZMF Ori,Oppo PM1
  IP Logged
HockessinKid
Seasoned Member
****




Posts: 1084
Re: SE84 clone headhone amp
Reply #18 - 05/19/21 at 17:27:12
 
GroovySauce,

Mainly referring to applying dynamat or other materials internally to equipment chassis. Sorry, should have been more specific. Also, adding this stuff can reduce resale value of equipment.

I use heavy maple audio platforms under most of my equipment with footers. These do import a noticable improvement in clarity.

Using handi wipes or hosing down electronics ... well I'll leave that discussion to others😁

HK
Back to top
 
 

Nottingham Interspace TT w/ Audio Technica AT-OC9XML cart + Modwright PH 9.0XT phono OR Modwright modded Cambridge CNX V2 > CSP3-25th Ann. preamp > ZMA-25th Ann. amp > PI Audio UberBUSS > Caintuck Audio Lii15 Magnum speakers > Snake River Audio & ZenWave cables
  IP Logged
4krow
Seasoned Member
****


IMAGINE WHIRLLED
PEAS

Posts: 1606
Re: SE84 clone headhone amp
Reply #19 - 07/18/21 at 22:16:55
 
 I am impressed by the fact that you used quality output transformers in this build. They can have a big influence on the final outcome.

 I agree about the chassis being so thin. I just completed a preamp project with one of these and being OCD, I used big brass braces, silicone and Dynamat, plus added at least a dozen bolts to give badly needed clamping of the bottom cover to the chassis. I likely will not use a Hammond enclosure again. FWIW, in a medium to small enclosure, I found a supplier on eBay that makes a very sturdy chassis for a damned good price. The paint is excellent as well.

 I made a fine headphone amp designed by John Broskie years ago, with the circuit already built by one of the members here and haven't looked back since.
Back to top
 
 

Decware 34I.3 integrated amp/Forte' 3 bass amp/Velodyne SMS-1 bass mngmnt system/Decware ZOB speakers/Audio Nirvana 8" bass drivers/Xiang Seng DAC/ LR Audio Computer/Rega Apollo R CDP/Emotiva ERC3 CDP/BPT 3.0 power cond.
  IP Logged
funch
Seasoned Member
****




Posts: 151
Re: SE84 clone headhone amp
Reply #20 - 06/19/22 at 01:53:58
 
Made a little upgrade to my amp.





It's now a full blown '25'. I also installed four Tesla glass resistors. The sound is spectacular. Increased dynamics, clarity, resolution. The headstage is phenomenal. [Mic drop].
Back to top
 
 
  IP Logged
Pages: 1
Send Topic Print