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A Very Compact Hybrid Amp - Page 35

post #511 of 2203
3/19/09 at 10:41pm
Quote:
Originally Posted by MrSlim View Post
OK I want to see someone stuff a stepped attenuator in a 1455K1601 box..
I thought one you chaps had used that DACt style attenuator from taiwan..was plannning on getting that for my second CTh actually.
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post #512 of 2203
3/19/09 at 10:52pm
Quote:
Originally Posted by sachu View Post
I thought one you chaps had used that DACt style attenuator from taiwan..was plannning on getting that for my second CTh actually.
Keyid did, but he hasn't cased his up yet...
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post #513 of 2203
3/20/09 at 1:30am
Thanks for the advise Sachu, wiatrob.

I'm currently reading through pages and pages of info on both Alex's site and builder's thread (very detailed I must add). Things may or may not go smoothly but as long as I follow the directions carefully I think I'll be fine -- guess I'll find out soon enough what challenges lay ahead for both these projects. Thanks!

zk
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post #514 of 2203
3/20/09 at 1:34am
Quote:
Originally Posted by MrSlim View Post
Keyid did, but he hasn't cased his up yet...
yea, hope to get this sucker cased up soon. The "dact" style stepper is pretty close to the size of an alps, maybe little fatter; it should fit nicely in the longer case. Im so relieved that the sonicaps is working, thought something was wrong with my build. Now I can play with more caps without worry.
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post #515 of 2203
3/20/09 at 3:42am
Hey everyone, Here is a great deal on some nice tubes, some of you guys could split this up! Tube on the left with the convex anodes looks like my tungsol and was probably made by tungsol (tons of bass weight and clean clear highs). Not sure about the Motorola but it may be an old 50's RCA (Thick and sweet). Westing house looks like it could be a Tungsol, The GE's I'm not sure about (maybe they are GE or Tungsol). The last 3 RCA's are newer and could possibly be from Mexico or Canada, but at 80 balloon's for 10 tubes I would take my chances, hell, ya never know, maybe the non-US tubes sound good too.
http://cgi.ebay.com/10-NOS-RCA-GE-Other-Some-D-12BH7-Audio-Tubes_W0QQitemZ400037767287QQihZ027QQcategoryZ6462 9QQssPageNameZWDVWQQrdZ1QQcmdZViewItem"]http://cgi.ebay.com/10-NOS-RCA-GE-Ot...QQcmdZViewItem[/URL]



Nice looking RCA's, for me this tube was as smooth as it gets, too smooth in fact for my amp but with your SS output section it may be the ticket. (VERY TUBEY SOUNDING).
http://cgi.ebay.com/QUAD-RCA-12BH7A-...QQcmdZViewItem

Dont know a thing about it but for 15 bucks I may just buy it myself.
http://cgi.ebay.com/NOS-NIB-RAYTHEON...QQcmdZViewItem

Bad Ass Mofo'S, nice tube for a set of cans light on bass weight and rolled off at the top.
http://cgi.ebay.com/12BH7A-12BH7-RAR...QQcmdZViewItem
http://cgi.ebay.com/NOS-Tung-Sol-12B...2em118Q2el1247

Interesting English Tube, Bo dont know diddly, may be the biggest pork chop you ever ate or your bulldozer?!?!?
http://cgi.ebay.com/BRIMAR-12BH7-VAL...dZp1638Q2em122
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post #516 of 2203
3/20/09 at 11:36am
Quote:
Originally Posted by MrSlim View Post
< snip> I just got a 6DJ8, since CF was raving about them..
And what do you think of it? I notice the deals I pointed to are no more (Amperex 6DJ8 circa very early 60's white label Holland - $12 shipped?). I'm still loving the 2 of these I have, for rock variants at least... Even maybe better than the 6922 PQ I snagged for < $20. Maybe I'll bring a load of tubes to NYC & try to crawl through them & see what I think...

A CTH tube thread should probably happen pretty soon.
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post #517 of 2203
3/20/09 at 8:12pm
Group buy is now closed..we have 10 pairs spoken for..I have made the payment for the tubes..
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post #518 of 2203
3/21/09 at 11:34am
Quote:
Originally Posted by cfcubed View Post
And what do you think of it? I notice the deals I pointed to are no more (Amperex 6DJ8 circa very early 60's white label Holland - $12 shipped?). I'm still loving the 2 of these I have, for rock variants at least... Even maybe better than the 6922 PQ I snagged for < $20. Maybe I'll bring a load of tubes to NYC & try to crawl through them & see what I think...

A CTH tube thread should probably happen pretty soon.
i haven't had a lot of time to listen to it so far, but I do like it. I guess I haven't done a lot of "critical" listening for a long time, maybe I need to get my ears attuned to the nuances. I have noticed that there is lots of detail with them.. I listen more to classical, and jazz, as well as a lot of CBC Radio 2 at work. On Thursday night I listened to all 4 of the Oscar Peterson "Exclusively for my Friends", and they sounded very good. I started with a 12BH7a though, which a few others really like as well, and I thought was very dynamic. I was one of the one's who snagged that deal you mentioned..
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post #519 of 2203
3/22/09 at 12:13am
Quote:
Originally Posted by MrSlim View Post
One of the final prototypes:
What knob did you use MrSlim? Looking for a black one similar to this to match a black case, on the RK097 pot. I'm happy to modify the pot with heatshrink to get it to fit.

Is the black tube surround around the hole in the kit photos this bushing?

And thanks for all the tips, I'm building a few for myself and some friends so just wanting to make sure I get everything all in one go!

Cheers!
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post #520 of 2203
3/22/09 at 4:15am
Can anyone tell me what kind of sound quality I should expect from this amp? What other amps are it this league? Another amp I was considering was one of the Ibasso ones since they're nice and small. Is this one comparable?
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post #521 of 2203
3/22/09 at 4:25am
Quote:
Originally Posted by ppchiu View Post
Can anyone tell me what kind of sound quality I should expect from this amp? What other amps are it this league? Another amp I was considering was one of the Ibasso ones since they're nice and small. Is this one comparable?
It reminded me a lot of other tube hybrids like a Millett and Head-direct EF1. It has a nice rich powerful sound with Grados, and it takes the edge off the Grados nicely as well. The iBasso D10 is the only iBasso that can come close to this tube hybrid in sound quality, but it's not even close in power or refinement and the synergy with Grados is much better with the Cavalli Compact Tube Hybrid. The Cavalli amp could also drive very inefficient orthodynamic headphones that portable amps just can't drive hardly at all. I neglected to try it with my HD600, sorry - but I expect it to do very well there too.
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post #522 of 2203
3/22/09 at 5:04am
Thought it was about time I posted a few pics of my CTH/Bantam build.

Originally planned to use the extra room in the 1455K1601BK case for a nice pot, 1/4" jack and RCA's but soon realised that a small DAC could be fitted in the extra space instead. All board parts are standard BoM except for Nichicon electrolytic and Wima film caps.

The only problem encountered was a reversed D4P diode which caused two transistors(Q3P & Q1P) to fail, but very easy to fix. Would recommend anyone building this amp build in stages double checking everything as they go since there are a lot of parts on a small board, also check carefully for solder bridges. Still a few changes/tweaks to come, Power switch going on the rear, sonicaps for C4L/R and need to change output resistors(socketed to make this easy) as the gain is still a little high for lowZ headphones.

The overall sound is very detailed, fast with plenty of bass and drives all headphones I have tried with ease. The bass doesn't dominate but is there where it should be and is deep and powerfull. Nice clear sparkling highs, seems to do everything well.













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post #523 of 2203
3/22/09 at 5:14am
Quote:
Originally Posted by Forte View Post
Thought it was about time I posted a few pics of my CTH/Bantam build.

Originally planned to use the extra room in the 1455K1601BK case for a nice pot, 1/4" jack and RCA's but soon realised that a small DAC could be fitted in the extra space instead. All board parts are standard BoM except for Nichicon electrolytic and Wima film caps.

The only problem encountered was a reversed D4P diode which caused two transistors(Q3P & Q1P) to fail, but very easy to fix. Would recommend anyone building this amp build in stages double checking everything as they go since there are a lot of parts on a small board, also check carefully for solder bridges. Still a few changes/tweaks to come, Power switch going on the rear, sonicaps for C4L/R and need to change output resistors(socketed to make this easy) as the gain is still a little high for lowZ headphones.

The overall sound is very detailed, fast with plenty of bass and drives all headphones I have tried with ease. The bass doesn't dominate but is there where it should be and is deep and powerfull. Nice clear sparkling highs, seems to do everything well.
That is one sweet looking amp Forte....well done!!!
see you squeezed in a bantam in there..I have plans on doing that somewhere down the line.

Curious as to how are you doing the switch from analog to digital input?
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post #524 of 2203
3/22/09 at 5:52am
Quote:
Originally Posted by sachu View Post
Curious as to how are you doing the switch from analog to digital input?
3PDT toggle switch on back panel.

Bantam output wired to the bottom row of switch, 3.5mm wired to the top row and the centre row to the amp. Just have to make sure the L, R and ground all connect to the correct positions so they switch correctly.
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post #525 of 2203
3/22/09 at 5:57am
Quote:
Originally Posted by Forte View Post
3PDT toggle switch on back panel.

Bantam output wired to the bottom row of switch, 3.5mm wired to the top row and the centre row to the amp. Just have to make sure the L, R and ground all connect to the correct positions so they switch correctly.
Neat...should definitely give this a try in my CTH...looks like you did not install the on/off seitch or left out the heater switch..or am I trippin;

Also, what is that black ring at the top left corner in the back
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