Full range speakers, SE triode and T-amps |
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主旨寄件者更新日期
回覆 (531): Back!
testing 3
CFT
22-05-23
00:49:40
回覆 (530): Back!
testing 2
CFT
22-05-23
00:09:29
回覆 (529): Back!
testing....
CFT
22-05-23
00:07:17
回覆 (528): Back!
No update for a long while, have been just posting new gadgets, diy items and discussions on our local whatsapp group.  
 
Searching for a photos hosting site. Will find one. :)  
 
And then will transfer the topics and info from whatsapp to here!
CFT
22-05-10
14:15:46
回覆 (527): Digital boards for: PCM to DSD256, FIFO Reclocker w/ultra quality xtals, 16x FIR
These three digital processing boards have really caught my eyes, I think they are fun to be had.  
 
 
1) PCM to DSD256 hardware converter  
 
Using SRC4192+AK4137 chips  
with performance level rivaling Roon software conversion (but not as good as HQPlayer).  
 
https://www.diyaudio.com/forums/digital-line-level/358147-simple-dsd-src-beaglebone-19.html#post6704982  
 
2) FIFO reclocker with ultra low phase noise/jitter crystal oscillators  
 
The Well synchronized asynchronous FIFO buffer - Slaved I2S reclocker  
 
https://www.diyaudio.com/forums/digital-line-level/348074-synchronized-asynchronous-fifo-buffer-slaved-i2s-reclocker.html  
 
3)  16x Digital interpolation filter - up to 768 kHz : upsampling data for R2R dac chips ***  
 
Digital Interpolation Filter (FIR)  
 
https://www.kusy.audio/digital-interpolation-filter-fir/  
 
https://www.diyaudio.com/forums/digital-line-level/327043-16x-digital-interpolation-filter-drive-pcm56-pcm58-ad1865-768-khz.html  
 
***  
 
"Our investigation as to why OS and NOS do not sound the same has apparently succeeded in identifying Category B2 as responsible, without having isolated the exact mechanism which makes it's responsible. With an very important discovered modification of B2 to state, "Lack of an FIR interpolation-filter OR of a high-enough performing FIR interpolation-filter, which frees the DAC from otherwise audible processing 'artifacts'."  
 
 
B) RECONSTRUCTION/IMAGE-BAND HANDLING  
===============================================  
2) Lack of an FIR interpolation-filter, freeing the DAC from certain processing 'artifacts' , such as:  
a) time-domain signal echoes produced within Equiripple on-chip FIR filters.  
 
https://www.diyaudio.com/forums/digital-line-level/371931-makes-nos-sound-120.html  
CFT
21-08-08
21:15:28
回覆 (526): Updates and catch ups: Audial Dac, SATRI amp, SET sound
1) Audial 2021: USB to pcm interface and AYA 5 TDA1541A Dac kit available for purchase :)  
 
https://www.audialonline.com/blog/usb-interface-and-aya-2021-editions-poll/  
 
2) SATRI amp kit jointly presented by MJ magazine and Bakoon Products: 10W +10W, about usd700 (earlier this year)  
 
https://m.facebook.com/bpsatri/  
(check out Feb pages)  
 
https://www.seibundo-shinkosha.net/mj/?p=3217  
 
(in English:)  
https://www-seibundo--shinkosha-net.translate.goog/mj/?p=3217&_x_tr_sl=zh-CN&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=ajax,nv,elem  
 
3) Maybe here is why SET amps sound better to the ears than solid state amps do (check out the last paragraphs, a proper way to evaluate sound quality via speaker interaction?)  
 
http://croweaudio.blogspot.com/2019/11/es-600-horn-with-rcf-nd-940.html?m=1  
CFT
21-07-09
18:04:38
回覆 (525): ultimate, ultra low phase noise clocks for dacs
https://www.diyaudio.com/forums/group-buys/291925-tempered-master-clock-buy-81.html#post6429823  
 
This group buy is ending soon....but there will be a second one sometime in case one misses out....
CFT
20-11-29
15:18:02
回覆 (524): My comment on cryogenic treatment
CFT
20-11-28
01:10:54
回覆 (524): Another Dacs shoot out: three diy R2R dacs
This time we compared three non delta sigma diy NOS dacs in the same setting as before.  
 
1) Ryanj Distinction V3 i2s in TDA1541A with tranny out  
2) Miro1360 AD1862 with LME49997 out  
3) Local discrete R2R with tranny out  
 
Sources: for 1) and 2) pi3 i2s with iancanada FIFO (LifeO3); JLsound USB to i2s for AD1862 only  
 
Impression:  
 
These dacs presented us with similar R2R signature - mellow, non congested, musical sound, with great micro dynamics, good imaging and wide sound stage.  
 
I myself was surprised by the more vivid and lively vocals when the discrete R2R was playing...compared to those two classic chips... AD1862 had excellent dynamics and well rounded performance, high freq registers showed more colors and better 3D imaging, while TDA1541A could quite mesmerize you over to a jazz club kind of environment, perfect for playing vintage recordings..  
Each has its own merits...so cant say which one is absolutely better than the others, really depending on the type of music being played.  
 
One caveat, both AD1862 and TDA1541A are built with non boutique grade components, and no simultaneous mode was employed on TDA1541A. Upgrade parts are ready though, eg, Rhopoint resistor and polystyrene cap for the IV stage...and higher grade output transformers, etc.. so next round we expect to have further improved sound performance.  
 
JLSound USB to i2s was certainly another surprise.  
We tried using audiophile grade fiber interface USB cable vs reg USB copper cable, and, not much of noticable difference.. even compared with pi3 + ian FIFO (LiFeO3), we couldnt detect much of dissimilarities too....which means.....we have been pretty much brainwashed by i2s is good and usb is bad....as time was limited, we need to compare them again next time and see if thats really the case... :)  
 
CFT
20-11-27
22:36:24
回覆 (524): Another Dacs shoot out: three diy R2R dacs
This time we compared three non delta sigma diy NOS dacs in the same setting as before.  
 
1) Ryanj Distinction V3 i2s in TDA1541A with tranny out  
2) Miro1360 AD1862 with LME49997 out  
3) Local discrete R2R with tranny out  
 
Sources: for 1) and 2) pi3 i2s with iancanada FIFO (LifeO3); JLsound USB to i2s for AD1862 only  
 
Impression:  
 
These dacs presented us with similar R2R signature - mellow, non congested, musical sound, with great micro dynamics, good imaging and wide sound stage.  
 
I myself was surprised by the more vivid and lively vocals when the discrete R2R was playing...compared to those two classic chips... AD1862 had excellent dynamics and well rounded performance, high freq registers showed more colors and better 3D imaging, while TDA1541A could quite mesmerize you over to a jazz club kind of environment, perfect for playing vintage recordings..  
Each has its own merits...so cant say which one is absolutely better than the others, really depending on the type of music being played.  
 
One caveat, both AD1862 and TDA1541A are built with non boutique grade components, and no simultaneous mode was employed on TDA1541A. Upgrade parts are ready though, eg, Rhopoint resistor and polystyrene cap for the IV stage...and higher grade output transformers, etc.. so next round we expect to have further improved sound performance.  
 
JLSound USB to i2s was certainly another surprise.  
We tried using audiophile grade fiber interface USB cable vs reg USB copper cable, and, not much of noticable difference.. even compared with pi3 + ian FIFO (LiFeO3), we couldnt detect much of dissimilarities too....which means.....we have been pretty much brainwashed by i2s is good and usb is bad....as time was limited, we need to compare them again next time and see if thats really the case... :)  
 
CFT
20-11-27
22:32:11
回覆 (523): My comment on cryogenic treatment
My comment on cryogenic treatment on cables :)  
 
https://www.diyaudio.com/forums/construction-tips/359963-cryogenic-treatment-8.html#post6359943
CFT
20-10-04
16:00:25
回覆 (522): photobucket free account issue
Due to the latest free account policy of photobucket that allows only up to 250 photos, some *very minor* photos in this thread are to be removed by Oct 1, unfortuately...o>_
CFT
20-09-29
18:35:32
回覆 (521): Delta sigma vs R2R?
We recently had a brief dacs shootout: Katana, Iancanada both synced ESS 9038, diy R2R discrete and AD1865/62.(system: ptt2s/26 dht preamps, 2A3 amp and feastrex field coil 5")  
 
...and all agreed that R2R discrete or old dac chips (Ad1862/5, TDA1541A and alike) still have the upperhand on the musicality and vocals departments...
CFT
20-09-09
14:20:47
回覆 (520): harmonic distortion profile
Proper harmonic distortion profile is the key to musical reproduction.... (following musical instruments)  
 
1) Jean Hiraga  
https://sound-au.com/tcaas/hiraga1.htm  
 
2) AudioExpress  
https://audioxpress.com/article/Musicality-and-Distortion-A-Conversation  
 
3) tuning harmonics  
https://www.diyaudio.com/forums/pass-labs/327746-h2-5.html  
CFT
20-09-09
13:55:55
回覆 (519): STC, nested loops revisited and Aikiko too!
Wow, great potential to make excellent amps!  
 
1) https://www.diyaudio.com/forums/pass-labs/36398-gc-supersymmetry-68.html  
 
2) https://www.tubecad.com/2018/02/blog0411.htm  
 
3) https://www.tubecad.com/2015/06/blog0325.htm
CFT
20-05-12
17:55:11
回覆 (518): JELabs
http://jelabs.blogspot.com/?m=1  
 
He is active again in this new blog site after moving back to the US...  
 
Someday will like to build his vintage Altec speakers, in the meantime, have the mini VOTT (posted before) in the plan...  
 
Now with a couple of 1” CDs in mind for the QSC clone waveguides:  
Beyma CP380M, RCF ND350
CFT
20-05-12
13:13:25
回覆 (517): Darling amps
https://web.archive.org/web/20070507040519/http://www.geocities.com/TimesSquare/1965/darling.html  
 
The above link is about various Darling amps.  
 
The intriguing part of this design is... both drivers ( left and right channels) share one single cathode resistor (and cap)....  
 
At first glance...it didnt seem right because there will be crosstalks created thru the feedbacks from both channels... indeed..thats the idea.. and its effect is: an extraordinarily wide image is created.  
 
And I call that a convolution. :)
CFT
20-04-11
22:36:22
回覆 (516): Kokoriantz amps (2)
Amps designed by Kokoriantz (2)  
 
7) https://www.diyaudio.com/forums/chip-amps/302190-30watt-class-phoenician-amplifier.html  
 
8) https://www.diyaudio.com/forums/solid-state/319905-phoenician-follower.html  
 
9) https://www.diyaudio.com/forums/chip-amps/300933-my_fef-2-a.html  
 
10) https://www.diyaudio.com/forums/solid-state/331525-simple-class-amp-using-jfet-output-devices-3.html  
 
11) https://www.diyaudio.com/forums/solid-state/320138-bi-circleton-8.html  
 
12) https://www.diyaudio.com/forums/tubes-valves/297206-andrea-democratic-hybrid-amp-luxury-sound.html
CFT
20-03-29
01:21:52
回覆 (516): Kokoriantz amps (2)
 
1) https://www.diyaudio.com/forums/solid-state/329553-sublimed-jlh1969.html  
 
2)https://www.diyaudio.com/forums/class-d/337182-sublimed-tpa3116d2.html  
 
3) https://www.diyaudio.com/forums/chip-amps/268802-lm3886-lme49720-composite-amp-9.html  
 
4) https://www.diyaudio.com/forums/solid-state/341788-jlh69-mosfet-class-ab-80w.html  
 
5) https://www.diyaudio.com/forums/chip-amps/296439-lm3886-singing-hell.html  
 
6) https://www.diyaudio.com/forums/solid-state/344029-classb-mosfet-amplifier.html  
CFT  
20-03-14  
19:58:57  
回覆 (514): Germanium amps
CFT
20-03-29
01:12:20
回覆 (516): Speakers
Speakers:  
 
Still psyched and looking forward to working on the followings...  
 
1) replacing the Aura Whisper 2" tweeter with its baby brother Aura Cougar (1" with 3/4" titanium cone) to make the Linkwitz Pluto more of a truer omni directional speaker (from current 3kHz to 10KHz omni)  
 
2) A small fullrange cone driver (2") loaded on the 17" wide ebay waveguide with good controlled directivity down to 600Hz.  
 
3) my Altec mini VOTT, using Altec 406 and an 1" CD loaded on a PVR waveguide..
CFT
20-03-14
20:01:58
回覆 (515): Kokoriantz amps
Amps (II)  
 
by Kokoriantz  
(Is this gentleman a genius or what? :)  
 
1) https://www.diyaudio.com/forums/solid-state/329553-sublimed-jlh1969.html  
 
2)https://www.diyaudio.com/forums/class-d/337182-sublimed-tpa3116d2.html  
 
3) https://www.diyaudio.com/forums/chip-amps/268802-lm3886-lme49720-composite-amp-9.html  
 
4) https://www.diyaudio.com/forums/solid-state/341788-jlh69-mosfet-class-ab-80w.html  
 
5) https://www.diyaudio.com/forums/chip-amps/296439-lm3886-singing-hell.html  
 
6) https://www.diyaudio.com/forums/solid-state/344029-classb-mosfet-amplifier.html
CFT
20-03-14
19:58:57
回覆 (514): Germanium amps
Amps (I)  
 
with germanium transistors  
 
(I never worked on germanium the material at all..but this has reminded me of my research advisor (once IBM chief scientist) and his still-in-contact advisor John Bardeen whom invented the transistor at end of 1947.  
 
1) How about a class A PNP Germanium JLH 1969 amplifier, anyone?  
 
Here it is:  
 
https://m.intl.taobao.com/detail/detail.html?spm=a21wu.11154615-hk.list.11&id=592463740962&item_id=592463740962  
 
RMB 235 or USD 34 (stereo kit)  
RMB 435 or USD 62 (stereo assembled)  
 
2) oh, and some other germanium SE preamps here too.  
 
https://m.intl.taobao.com/detail/detail.html?spm=a21wu.11154615-hk.list.13&id=35816855235&item_id=35816855235  
 
https://m.intl.taobao.com/detail/detail.html?id=574216945656&item_id=574216945656  
CFT
20-03-14
19:57:54
回覆 (513): Newly developed dac chips
Almost missed this one...  
 
4) Star Pure DSD dac  
 
No, not about the Signalist DSC dac module used within which already posted before, but this hardware PCM to DSD conversion chip from Comtrue, CT7302PL, which compared favorably to the PCM to DSD software solution using HQP player with "same details and same sound stage, though HQP based system a little bit softer " reportedly from the link here:  
 
http://www.audiodesignguide.com/DSC2/index.html
CFT
20-03-14
19:49:14
回覆 (512): Newly developed dac chips
Newly developed dac chips:  
 
1) From Rohm:  
https://www.rohm.com/news-detail?news-title=rohm-expands-its-da-converter-product-line-up-for-high-fidelity-audio&defaultGroupId=false  
 
2) AK4499 proliferating in the dac products market now  
 
3) AKM chip set AKM 4191eq + AKM4498eq (separating digital and analog)  
 
https://www.akm.com/global/en/products/audio/audio-dac/ak4191eq/
CFT
20-03-14
19:47:28
回覆 (511): MJ Audio Festival 2020 cancelled, MJ magazine, 01A tube
Due to the coronavirus attack in Japan, MJ Audio Festival this year in March in Tokyo has been cancelled...too bad..  
 
So I was looking today.....  
 
Here is a little history on MJ magazine, the organizer.  
 
MJ magazine, its first issue in1924 was published a good 96 years ago!  
 
What were they using at that time to build radios, one might wonder?   
 
How about 01A DHT tubes?  
 
Indeed! It caught the time when 201A was born (1923)!  
 
Actually 201A is a predessessor of UV201 which was created in 1920, yes, which celebrating its 100th year birthday this year! wow,  thats a hundred years ago! ^O^  
 
Info on 01A tube  
https://www.radiomuseum.org/tubes/tube_ux201a.html
CFT
20-03-13
20:52:58
回覆 (510): MJ Audio Festival 2020 cancelled, MJ magazine, 01A tube
testing
CFT
20-03-13
20:51:24
回覆 (509): photos hosting issue again...
Photobucket has changed its hosting rules again...  
 
Free accounts are now allowed for 25M of monthly bandwidth for viewing only (not 25M of storage limit)..  
 
So far it has been 280M of bandwidth used in my account, wow, thats quite a lot!  
 
It will be reset to zero at month end though and photos will reappear, until viewing bandwidth gets over 25M again....  
 
Will find a good solution.. thanks for your viewing. : )
CFT
19-09-22
20:19:54
回覆 (508): Iancanada diy toys
oh well..my apologies on the photos quality.  
Its photobucket I have been using.....and you know the problem they are facing..  
 
Photos are blurred if viewing from a PC, but are still somewhat OK on a mobile phone.  
 
Please view from a mobile phone in the meantime, as there will be a solution sometime later.  
CFT
19-07-23
22:19:15
回覆 (507): Iancanada diy toys
Iancanada modules:  
 
Pi3 + FiFoPi (reclocker) + ESS controller + ESS 9038 dac + IV stage + LifePO4 batteries charging controller board.(from web)
CFT
19-05-14
12:48:25
回覆 (506): Iancanada diy toys
Our whatsapp diy group had a large group buy of long anticipated Iancanada 2019 modules (FiFopi, 9028/38 dacs, IV stages, batteries charger board, etc.. )and we have started putting them together....more stories later.  
 
https://www.diyaudio.com/forums/group-buys/207438-ian-asynchronous-i2s-pdif-fifo-kit-buy-318.html#post5727881
CFT
19-05-14
12:35:18
回覆 (505): Happy Chinese New Year
祝大家新年快樂,心想事成,萬事勝意!  
CFT
19-02-05
02:10:42
回覆 (504): early 1950s WE755A
Went to a friend's Ping Pong training place to check out his WE775As, housed in a set of wooden antique radio cabinets as young as him. (Him being a member of the Chinese ping pong players team during the Ping-pong diplomacy in the 60s, some photos were posted two years ago)  
 
Well, what can I say, I can understand why this early 1950s pair should fetch over usd10k.. so coherent, beautiful vocal, its really musical~!  
 
Power amp: Quad 303  
Preamp: FM Acoustic
CFT
19-01-19
23:03:09
回覆 (503): Dynavox 3.5" full range
http://feleppa.com.au/speakermeasmid.html  
 
Tested out the Dynavox LY302F the other day.  
 
Very nice driver! Overall better than TC9 for sure~!  
 
No wonder its ranked the highest in the link above.  
 
No woofer assistance needed.
CFT
19-01-19
22:27:45
回覆 (502): Happy diy in 2019~!
Happy New Year!  
 
January 2019 marks the 10th year anniversary of this thread, amazing itsnt it, its now 10 year old! (Thanks to Tanuski's early encouragement on the committment part.)  
 
And, really, hifi (stereo) diy is a fun hobby.  
 
It combines your hifi understanding and experience, your electronic knowledge, mechanical skills, esthetic/artistic senses, together with your creativity and innovation (or your technology transferring ability) into *making something of your own*, that pleases your eyes, boosts your endorphins, and brings about the aural pleasure, which all leads to and for your music enjoyment!  
 
Hope your new year resolution all set and best DIY wishes to us all in 2019~!
CFT
19-01-01
17:16:00
回覆 (501): PTT205 PP Amp
Congrats, thats an excellent tube, a sleeper and a real gem indeed.. :D  
 
The original builder of the amp using this tube is no longer with us... so sad... :(  
 
I can tell you that he bought a full box of them NOS... but have no idea where they are now... unfortunately. Grab this French tube quick if you happen to bump into any...  
 
As for the circuit, its just a very common PP amp circuit, heavily biased but nothing special..though I dont have the voltages in use to say, the output transformer came from a junk vintage English amp which by accident brings the synergy into the play (PP sounds like SE)..  
 
Happy listening!  
 
CFT
18-11-01
22:33:15
回覆 (500): PTT205 PP Amp
Hello,  
Were do find schematic and tubes for PTT205?  
i use those tubes in SE amp.  
Regards  
phoenixOZ
18-10-30
19:08:24
回覆 (760): Zenith fullrange speakers 1958
Finally..got this pair of Zenith speakers circa 1958 on ebay. (^_^)
CFT
18-08-09
21:06:24
回覆 (759): Holey on ebay waveguide
Quite exciting actually as it is very promising...I mean it works very well! (^_^)  
 
Showing that a small full range can work nicely in place of compression driver on horn/waveguide.  
 
Eventually will use minidsp for the EQ and xover functions to a woofer.
CFT
18-07-23
13:58:25
回覆 (758): Holey on ebay waveguide
Last night we tested briefly the Peerless TC9 and one of my favorites - Coral holey Basket (Sony) speakers on waveguide.  
 
Photo showing the Sony Holey loaded to the ebay waveguide.  
 
Throat size is 2" and the paper cone is 2.5" in diameter. Thats a quick trial...will need to smooth out the rim of the throat to avoid rough freq response at upper highs.  
 
Its open backed and so it sounded like when its mounted on an OB panel in terms of the big sound stage, but a bit more dynamic and having same imaging across the room in the listening area. Need more listening time in a proper set up and will have more comment later. (^_^)
CFT
18-07-23
13:48:34
回覆 (757): Another 1" waveguide
The idea of making a synergy horn is to achieve a sort of single point source with directivity controlled over a large range, say down to below 500Hz... Danelys can go down to below 100Hz IIRC.  
 
That ebay horn posted with 2 inch throat can control directivity to ~700Hz...and it can be done by extending the mouth to a wider width for lowering it.down to ~400Hz or so...  
 
The beauty of it ...is that same thing kind of can be achieved by using a single driver (with no xover at critical freq range say 700hz to 7khz where ears most sensitive), guaranteeing phase coherence... though it cannot go down as low but with a woofer say a 15" to pick up the directive continuity....its certainly good.  
 
Power handling wise...say using Aura Whisper as its a full range unit..designed to handle some 60w max...if its only respobsible for a few.hundred hz up...then loudness is not of a concern....it has 84db efficiency but there will be some gain provided by the waveguide so efficiency could come up a notch...or so....but need to look at the required EQ as well...  
 
Here is what i am talking about... very nice response curves after eq and with controlled directivity.down to ~500Hz.  
 
techtalk.parts-express.com/forum/tech-talk-forum/59712-2-aura-whisper-waveguide-loaded
CFT
18-07-19
22:34:01