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A New Hybrid from Indeed Hi-Fi Labs: does this look fun? - Page 22

post #316 of 355
Quote:
Originally Posted by Judge Buff View Post
The one mod that I really think made the most sonic impact on my Indeed was the addition of the 10K uF cap on the ps.
Yeah, I didn't mention I did this too, even better than 6800uf, tube on booting really shines, I mean visually . Hmm. Now I'm thinking that I have cheap PS cap in there. How could low ESR PS impact the SQ? I it only in faster handling the lows?
Quote:
Originally Posted by Judge Buff View Post
Oh yeah, Marcello, if you want your tube amp to sound more "analytical," I'd suggest that you invest in a Telefunken or Siemens E88cc. ... Enjoy!
Hmmm. And I though I finished with modding this amp However, I don't want to spend loads of money on this everything. When I was buying the Amperex, I chose because someone said,"Everything from Holland is good", that summed it all in the time I was browsing all those forums. I Still would like different SQ.

Judge Buff, would you recommend me

{search ebay for ""E88CC SIEMENS NOS""}(must be in quotes), one item should come up ?

it was the cheapest I found, I can't see the difference in Siemens for $15 and for $150, they look the same to me

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post #317 of 355
Has anyone noticed the G2 version? Looks like they added more heat sinks.
post #318 of 355
Hello everybody! Hope, somebody still has attention on this preamp. Forgive me my german-english.. I bought recently the G2 version on ebay, it still coming.. I definetly overpayed, but they do not sell it in Germany.. By the same time, i took a book from Library. It´s called: Tube Projects from 6-60V. Authors name is Burkhard Kainka. I found a lot schematics on such amps, also Hybrid like this. It runs also from 24V. Uses same type of tube and looks very similar. I will compare it with Indeed`s stuff when i get it.. The Autor of the book suggestes to raise the voltage to 27V also by building AC block by yourself and make it better noise resistent.. I dont have enough idea about this stuff, so i will leave it as it is and if i dont like the sound, will try to change the tube.. It means- everything new is well forgotten old.. This book is fun, it shows many ideas of using "high voltage" tubes with less power.. Like making EL34 or EL504 or EL 95 work just from a few Volts. 6.3, 12, 24 etc. It`s interesting. If you expect to drive 600 Ohm headphones only from this preamp, you can leave many parts of the schematic out and get better sound quality. It looks so simple, i ll try out to build one.
I have a question: I bought recently an endamp from Experience tech. It gives 2x 30W and runs 2 x ECC 83, 8 x EL 84 tubes. You can find an info on their page:
EXPERIENCE electronics - Endstufe Quadriga Stereo 2 x 30 W
It needs a preamp, does it?
So, what should i do? Use an Indeeds preamp before (impedance ok?) or connect it directly to my Roland USB Interface? Or take an preamped signal from my NAD 312? (makes no sense?). Sorry for the silly question, i`m musician and know how to make sound with hands... Also, does it works well to let the signal from Indeeds preamp go into NAD end section? I wont to drive Sansui SP 1200 with it. (They are sensitive enough- 92db)
Thank you a lot!
post #319 of 355
yes you can use the Roland USB Interface as a source if it has RCA line outs to drive your NAD which in turn drives the speakers.
post #320 of 355
Does anyone or can someone point me where I can find the test points to adjust the bias trim pots on the G2?
post #321 of 355
Quote:
Originally Posted by john57 View Post
yes you can use the Roland USB Interface as a source if it has RCA line outs to drive your NAD which in turn drives the speakers.
Thank you for the answer!
I could connect Roland USB directly to amp. It works well, Roland seems to give even more power then needed.
Right now i connected Roland USB to Indeed G2 preamp and then to the End-Amplifier i descriebed above (2x 30W 8 Ohm). Sounds just great! It was a surprise, that my speakers- Elac EL75 II do better with this equipment as Sansui SP 1200... Sound is much tighter, precise, warm and it gives incredible bass. It seems to produce much more sound without distortion compairing to Nad 312 i used before. I decided not to sell Elac`s =)
Yesterday i rolled the Chinese tube on Indeed to NOS Jan Sylvania 6922. I adjusted BIAS by ear. Sounds better, sometimes to sharp. I hope it will dissapear when tube burns in. I was able to check Bias today- it`s 37 mA on both channels however trims are not same position. Funny i could do it by ear =) I should try to calculate optimal setting for this tube. Sounds good so far. Should i try to modify this preamp? Leave headphones jack out, bypass source switch, replace volume trim with resistor. (I have a volume on Roland and end-amp) make a alluminium case for it with enough cooling space.. Capacitor seems to be different then G1- its 25V 6800 uF. No need to change? I have also another selfmade power supply- 24V 1.5A. There is time delay switch in the signal path. It connects after 3 seconds after turn on. Schould i remove it also? I believe to reduce noise level by leaving all this stuff out. Could somebody help me with advice?
Thank you a lot!
Have a nice day!
post #322 of 355
Here is a link to one of the most worthwhile mods you can do to these amps...
Starts about half way down the page...
Add the Bias Capacitor...it's missing!
post #323 of 355
Bias Setting:

I have seen many people wonder how to set the trim pots...
The pot sets the bias voltage on the cathode of the tube.
I have seen it suggested that it be set at 16 to 17 volts as measured at the anode of the tube.
The proper setting is to measure the voltage at the positive terminal
of the output capacitor. The reading should be 1/2 the supply voltage
or 12 volts in this case. On my bravo this gave me 15.75 volts on the
anode of the tube. Hope this helps people with setting their bias point.

Happy listening!
post #324 of 355
which output cap are you talking about? I have the G2 model and the one issue I have with it is very high gain. I was told by Indeed that the RCA inputs will overload at 1.5v which seems to be low.
post #325 of 355
Quote:
Originally Posted by john57 View Post
which output cap are you talking about? I have the G2 model and the one issue I have with it is very high gain. I was told by Indeed that the RCA inputs will overload at 1.5v which seems to be low.
My comments apply only to the G1 version, not the G2 version with the double heat-sinks on the MOSFETs.
I do not have a G2 to study or the schematic to it.
post #326 of 355
Quote:
Originally Posted by Avro_Arrow View Post
Here is a link to one of the most worthwhile mods you can do to these amps...
Starts about half way down the page...
Add the Bias Capacitor...it's missing!
I do recommend this little mod most highly... You may end up with your amp sitting up in the air on 4 legs like mine is now, but it's worth the lack of visual aesthetics. This mod is probably more important than any other I've done. The amount of definition it brings to the music is the greatest yet.

Based on A_A's advice, I placed two 16V 680uF motherboard (Nichicon HM) capacitors in the position shown in his fingernail photo in the Bravo thread. I have no idea if smaller capacity caps would make any difference in the sound. All I know is that each tube has sonic nuances that have not been apparent before. As good as I thought the amp sounded before, it sounds better now... cleaner, smoother and much, much more precise. I understand what he says about the sound having more "punch" now. It's due to the precision that each instrument and voice exhibits, especially percussion instruments.

This mod really allows each tube to shine. "Bass" tubes have more profound bass. 3D tubes have more precise environments. Soundstages are larger. The top end seems expanded. I could go on, but I think I'll just enjoy the music

Only caveat I have is to make sure that the capacitors are oriented correctly: positive toward the socket with the cap stripe toward the volume knob.
post #327 of 355

Well I finally found time to do the mods on the (6N11) Indeed. I use the 10K for the PS (really enhanced base (?) then added the Bias caps and bought "stands" from lowes so the caps clear.

I have the IRF510 Mosfets for it and am wondering if the will make a noticable difference on the 6N11 . The bias caps really brought the amp out! It has NO trouble driving the 702's. 

BTW I'm running a '65 mullard in it .

post #328 of 355

The IRF510's made a noticeable difference on my Bravo. Cleaned up the high range even more. You will need to give

them at least twenty hours of burn in before they really start to sound their best though.
 

Quote:
Originally Posted by ovrclkd View Post

Well I finally found time to do the mods on the (6N11) Indeed. I use the 10K for the PS (really enhanced base (?) then added the Bias caps and bought "stands" from lowes so the caps clear.

I have the IRF510 Mosfets for it and am wondering if the will make a noticable difference on the 6N11 . The bias caps really brought the amp out! It has NO trouble driving the 702's. 

BTW I'm running a '65 mullard in it .

post #329 of 355

I've got the mother lode of Indeed/Bravo info, pm me for details... Easy bias info, etc. I'm only 1/3 through one thread, but these guys are into these little amps as heavy as we are apparently. This may not be a revelation to most of you, but it was to me as I haven't been there in a long time. I haven't gotten far enough to know if they are modding heavily as the early pics look to be stock.

 

I'd post the url, but I didn't know if hf would get po'd and ban me. Lecky's countrymen seem to be the most involved in the forum...


Edited by Judge Buff - 5/22/10 at 9:36am
post #330 of 355

my switching 2A indeed PSU blew up. Opened her  up and the KA3842A SMPS controller was all black and obviously had gone kaput :/ Looked like some chinese no-name manufacturer so ordered a Fairchild-Semiconductor KA3842ACS along with 2 Panasonic FC 470uF 35V caps that do some final smoothing on the 24V end of the PSU to replace some crapola stock ones.

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