Paradisea DAC

F-100 · « **Reply #180 on:** 14 Dec 2006, 02:07 pm »

I sent him an email inquiring on the Bendix tube and here is his reply.

Dear xxxxxxxx,

Thank you, I have received your e-mail.
I am listen to the music with the vacuum tube amplifier of my own work.
I think that it is the best way the tube amplifier
was handmade with own like tubes and parts by DIY.

I have current stock 24pcs BENDIX 6385 Red Bank Type TE21 in Military
Boxes
(All these tubes are all tested, matched pair(almost same operation),
all same manufacture date(DATE PKD:11-64),
same internal construction and in Military boxes.).

These tubes has Bendix logos, Made in U.S.A, rot number and more
printed on tubes.
These tubes are NOS(New Old Stock) and good condition.

Thank you for your interesting of Bendix 6385 tubes.
Please inform me how many pieces you need these Bendix 6385 Redbank
Tubes.
Please inform me your shipping address in detail.

As for Method of Payment,
I cannot accept paypal payment
I would like to request cash Japnese Yen or U.S.Dollars (by enclosed
registered mail).
Also, I can accept U.S.P.S " International Postal Money Order" in
U.S.Dollars
by enclosed registered mail.
I think this payment method proper for U.S.P.S " International Postal
Money Order".

As for Shipping Method and Shipping Charges,
EMS (700g) shipping charges from Japan to U.S.A. (your address)
+ exchange charge(fee) +handling = 3,000 yen => about 26
U.S.Dollars
(International Express Mail Service=Registered Airmail).

I will inform you when I have received your registered airmail.
Also, I will inform you shipping information with EMS number
when I shipped these tubes to you by Japan Post EMS.

I will send e-mail attached photo of BENDIX 6385 Red Bank Type TE21
in Military Boxes.
Please look this photo by another e-mail.

Regards,
Junji Kouchi

tdangelo · « **Reply #181 on:** 16 Dec 2006, 03:37 pm »

any opinions on how long a tube will last in this DAC?

Thanks

Tony

Scott F. · « **Reply #182 on:** 16 Dec 2006, 03:49 pm »

MHDT is hitting the tube with about 100 volts so conceivably the tube could easily last 10 to 15 years if not longer (assuming 3-4 hours per day and all weekend). Who knows, with as low of voltage as this tube sees it could last even longer than that.

tdangelo · « **Reply #183 on:** 16 Dec 2006, 04:15 pm »

thanks Scott - thats good to know

I've been breaking in cables and it's been on 24x7 for about a week or so

Tony

Soundbitten · « **Reply #184 on:** 17 Dec 2006, 10:23 pm »

http://cgi.ebay.com/TDA1545-TDA1545A-Non-OS-TUBE-DAC-Paradisea_W0QQitemZ120065972258QQihZ002QQcategoryZ14978QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Builder Brad · « **Reply #185 on:** 21 Dec 2006, 10:47 pm »

Hi

I have just upgraded the output op amp in my Paradisea DAC following the sugestions put forward bt Legared and Occam on page 10 of this thread.

I used an OPA2107 to replace the APA2604 - thankyou Occam for the tip, and by-passed the + and negative rails to gnd with a 10uf tant and 0.01 ceramic disc capacitor in parrallel following Legareds images and earlier posts. The only thing I could not do is fit the 0.22uf foil capacitor between + and - as the capacitor I have is just too large - I am considering possibly cutting the case to get this to fit if I knew there was benefit in fitting this additional capacitor.

this was a very easy mod - taking about 10 minutes, and I was using a soldering iron with a large tip, so the op amp was a bit fiddly.

I have not really had time to listen to the DAC but initial impressions are positive and the Paridisea has lost some of its fuzziness

is it worth starting a thread dealing with mods for this piece of kit?

topround · « **Reply #186 on:** 22 Dec 2006, 01:53 am »

I just changed the output caps on my paradisea with Sonicaps 4.0( only ones lying around)
Much lower noise floor and extended highs. Took about 6 minutes to do and really helped. Going to bypass these caps with .22 platinum caps next. See what that does.

This is a fun hobby.

Scott F. · « **Reply #187 on:** 22 Dec 2006, 02:24 am »

I knew it wouldn't take long for one of you guys to get out your soldering irons

Builder Brad · « **Reply #188 on:** 22 Dec 2006, 05:19 pm »

Hi guys,

I have a couple of 0.22 uf Audionote copper foil signal capacitors - would it be possible to replace the 1.5uf output caps in the Paradisea output with these and then possibly by-pass with 0.001 in the same flavor in the future, or do I need to go with the largest value that fits inside the case + a small by-pass value?

Brad

Occam · « **Reply #189 on:** 22 Dec 2006, 08:18 pm »

Hi Brad,

Thanks for the update on your progress. I really like the Paradisea architecture. The single opamp/channel feeds the very high impedance load of the tube grid on the cathode follower, resulting on minimal demands on the opamp. I really do like the OPA2107 and haven't found a situation where I prefer the 2604, or the 2132/4. IMO, it, along with the 627/637 (but not requiring a single to dual adapter) is the quitessential 'Burr Brown sound" opamp. If you prefer to optimize the tube sound solely through tube rolling, the National LM4562 suggested by Legarem might be ideal. I currently have one, in addition to 2 opa2107 running in my Zhaolu 2.0 dac and I'm very impressed.

If you're looking for a .22uf (that value is not set in stone) cap for the opamp's rail to rail bypass you might consider the R82 from Arcotronics, MKP1817 from Vishay or the Seimens/Epcos B3252xxx caps. These are all radial leaded stacked polyester film caps ideally suited for ps decoupling. These are all available from RS in Europe, and the Epcos are available in the States from Digikey -
http://dkc3.digikey.com/PDF/T063/1285.pdf
Ideally, you want to minimize the inductance of ps decoupling caps by both the construction, radial orientation, and choosing the lead spacing so as to minimize the total trace and lead length to the power pins and ground.

As to the value of the output coupling caps, unless you know you're going to be driving a high impedance input power amplifier (many tube amps will typically have input impedances of 100-250kOhms), I'd recommend at least .47uf for the coupling caps. You can check the highpass -3db point with the formula -

f = = 159,155 / (R x C)
where C is capacitance in microfarads, uf
where R is the input impedance of the load (the amp or pre you're feeding), in Ohms
and f is the -3db down (pole) frequency in Hz (Hertz), or for you really old farts cps (cycles per second)
Generally, I aim for a pole frequency of 10Hz or below.

If there is interest, I'd think a thread in the Lab on Paradisea mods would be great fun, save for the fact that I don't have one. But there are at least 3 NYC Ravers that do. It would be ideal if they'd participate and we could piecewise modify the dacs and actually have a baseline version to compare it to. Its a more definitive approach than making a mod and then having to say that 'I think??? its an improvement' without being able to make a direct comparison. We could have mod/listening/comparison sessions at Chez Occam and really annoy my wife. Any takers? Regardless, someone who actually owns a Paradisea should start a Lab thread.

FWIW,
Paul

Builder Brad · « **Reply #190 on:** 23 Dec 2006, 02:00 am »

Thank-you Paul (Occam)

I will leave those output caps alone until at I can get some with a higher value, and possible by-pass with higher quality, lower value caps.

Hopefully I will be able to post impressions of my 1st mod on this DAC

Brad

topround · « **Reply #191 on:** 31 Dec 2006, 03:52 pm »

I replaced the output caps with Sonicap 4.0's and then bypassed these with Platinum .22's
I am hearing extreme detail and very fast transients. The noise floor is lower as well.
It is like seeing music thru a sheet of glass, extremely clean and revealing and effortless.
Everything is displayed at once with no fuss. No stress. no grain, just clarity and speed.
I liked the sound of the Paradisea but thought it needed a lower sound floor and a little more speed.
Being tube driven these may be characteristics that cannot be changed.
I am still lacking a little prat that opamps provide.
(The opamp will be replaced next, not sure if that will help, but worth a try.)
I am also using a Bendix tube.
Both tube and caps need to be burnt in, so things can change.

I think this Dac may be on it's way to greatness

I hope

R Browne · « **Reply #192 on:** 10 Jan 2007, 11:13 pm »

I'm expecting delivery on a Paradisea DAC shortly and am looking for recommendations for a digital cable to be used between my CDP used as a transport and a DAC. This is my first experience with a DAC as I've always used a one box CDP and I'm not very knowledgeable about digital cables. Favorite cables anyone?

Thanks,

Robert

GHM · « **Reply #193 on:** 10 Jan 2007, 11:55 pm »

Quote from: R Browne on 10 Jan 2007, 11:13 pm

I'm expecting delivery on a Paradisea DAC shortly and am looking for recommendations for a digital cable to be used between my CDP used as a transport and a DAC. This is my first experience with a DAC as I've always used a one box CDP and I'm not very knowledgeable about digital cables. Favorite cables anyone?

Thanks,

Robert

Congrats on the purchase!! I would put more stock in the transport than the cable. I've heard this Dac on 4 different transports..it sounded different on all four of them. Try a DIP or similar device with the Paradisea. The sound is sure to improve. Blue jeans cable makes a nice and sturdy digital cable. It won't break the bank either.

bpape · « **Reply #194 on:** 11 Jan 2007, 12:05 am »

If you want to maintain a good 75 ohm connection (which is important on digital and video - unlike analog audio), I'd try something with a BNC on one end and an Eichman bullet on the other end - or Eichmans on both ends. Talk to Wayne at Boulder Cable about the Nitro.

One of the reviewers darlings at a somewhat reasonable price (everything is relative) is the Kimber Illumination D-60.

Bryan

NewBuyer · « **Reply #195 on:** 11 Jan 2007, 01:18 am »

I have found a glass toslink to sound better with the Paradisea than any coax so far. Much better in fact. Do you have optical-out on your CDP?

R Browne · « **Reply #196 on:** 11 Jan 2007, 01:42 am »

Quote from: NewBuyer on 11 Jan 2007, 01:18 am

I have found a glass toslink to sound better with the Paradisea than any coax so far. Much better in fact. Do you have optical-out on your CDP?

No, just the regular digital RCA out on the CDP. I have a couple of Audio Note silver interconnects that I will try as a number of Audio Note owners have had success with them and Audio Note recommends a single run as a digital cable. I was looking for some general recommendations from Paradisea owners and thank you for the ones already received. In the trial and error scheme of things I'll see what works for me.

Gordy · « **Reply #197 on:** 11 Jan 2007, 01:58 am »

Quote from: bpape on 11 Jan 2007, 12:05 am

If you want to maintain a good 75 ohm connection (which is important on digital and video - unlike analog audio), I'd try something with a BNC...

The Stereovox HDXV is BNC to BNC and comes with adaptors if you don't want to replace the cdp's rca connector, which would be the best route by far! http://cls.audiogon.com/cgi-bin/cls.pl?cablintr&1171866937

Loftprojection · « **Reply #198 on:** 11 Jan 2007, 02:28 am »

Quote from: Gordy on 11 Jan 2007, 01:58 am

Quote from: bpape on 11 Jan 2007, 12:05 am
If you want to maintain a good 75 ohm connection (which is important on digital and video - unlike analog audio), I'd try something with a BNC...

The Stereovox HDXV is BNC to BNC and comes with adaptors if you don't want to replace the cdp's rca connector, which would be the best route by far! http://cls.audiogon.com/cgi-bin/cls.pl?cablintr&1171866937

I second the HDXV. I use it BNC to BNC with my modified RWA Squeezebox. In my application, contrary to another poster, the toslink is not as good, the BNC is superior by a good margin. I think it's important to consider the sender as well as the receiver. The Paradisea may be equal in quality for coax or toslink as a receiver, but sometimes it's the sender that as a poor connection wither toslink or coax...

echo1 · « **Reply #199 on:** 11 Jan 2007, 02:48 am »

I bought a PC link from here--http://www.diykits.com.hk/dac.html---and changed the rca to coax jack and can tell a difference between the coax and fiber.Coax is better.
Also bought blue jeans cable.
There is another transport that comes from china that are getting good reviews in head-fi here---http://www.head-fi.org/forums/showthread.php?t=205736. The product is available here----http://www.buyoyo.com/cgi-bin/ncommerce3/ProductDisplay?style=1&prrfnbr=9065256&prmenbr=152&CGRY_NUM=251&LANGUAGE=1&curr=USD
They both work with asio4all.