A Very Compact Hybrid Amp - Page 28

Must be Sachu's? It is a great amp - listening now to The Fugees with the RCA 6189, and it sounds pretty efing good...

Edit: Looks like it was Sachu's

yep..that's mine..
God..I have a huge shopping list of tubes I need to buy to roll on this little guy..Got a Slyvania 12AU7A doing duty..

I've said it before but really liking Amperex 6dj8s circa early 1960s... It could be my listening tastes or that I've few tubes costing > $10. Have a 6922 PQ white on the way & that'll be it for me for a while (always saying that tho

Trying out a new tube this morning - a CBS 7318. Listening to a UK pressing of Leon Russel's first album and it is sounding extremely good. Soundstage is super precise and the old school reverb in the recording is represented with a very authentic sound. Clapton's guitar sounds great as well.

Haven't spent enough time with it yet, but it may turn out being my favorite so far (paired with my DT880's).

Here's a very dark picture (it's snowing this morning)...

I agree - your Compact Hybrid was excellent with my RS-1 at the last meet. I didn't get to do a detailed comparison between the Millett SSH and EF1 but it was certainly not below their level, based on memory.

Im using GE 5314A triple meca and it sounds really lovely driving k501. Does extremely well with classical and vocals, plus now k501 has well defined bass. Im using kiwame 47ohm on R18 and a stepped pot.

This is just wrong...I just switched out a Sylvania 12Au7a with a 12BH7A Gold Aero..My God the difference in sound..SO much more livelier..Was looking at the prices for some of the more sought after tubes for this amp on ebay..made me gulp. Glad that it doesn't need more than one tube. Else no way could I afford a few bugle boys and other more sought after tubes..I really have fallen into a rabbit hole with this amp ..my first every tube amp..

keyid, the stepped pot you are using is the one from Taiwan I presume..how does it compare to the ALPS RK27...also I understnad a few of you chaps have used the vitaminq and the russian 0.22uF caps ..how big ar they..will they fit in the larger of the target cases?

So when is this amp finalized?

Reading all these juicy impressions makes me really, really want to whip out the soldering iron and build one for myself.

yes, i got the stepped "dact" like pot from overseas Taiwan, 100k. I cannot compare to the alps as I used a regular stereo log pot. The difference from the stereo log pot was significant. The sound became more cleaner and clearer. Its an incredible bargain imo, and ordered another for future builds. Took about a month to get to me.

I tried couple caps, wima, russian pio, and a polyester cap. I have little trouble with vitamin q's and sonicaps at the moment but im not even trying to get them to work. The caps are pretty big and are on legs standing above the board. Putting them under the board would work well as some builders have done and fit in the default case.

IMO the default yellow cap sounds the best so far. PIO and sonicap (when working) made the sound darker and murky, the amp seems to excels with fast transparent sound with the added smoothness of the tube. Though I didnt give them enough time to burn in, I figured it would not be as transparent as the default cap. This opinion however, was made solid once I switched cdp transport. I been using a denon dvd player feed to zapped zhoulo and with the default cap I did not like the highs. I got a sony dvp s7000 and that made a really big difference. The highs have little bit of sparkle with no glare. The sound became almost effortless and what I can describe as silky smooth. Kinda reminded me of presonus amp/dac smoothness. The amp seems to like better sources. I also think the kiwame has made the impact on the highs or it could be from using a lower ohm rating then the default, anyways get them from mouser cheap its worth experimenting. Jumping the r18's made the bass and mids shine but the highs became compressed. Was unable to distinguish the transient noise after the initial cymbal splash.

Yea tubes are addicting! I have some 12au7's from my soha and rolled the following:
GE 6680
Amprex 7316
Tele smooth plates
Brimmar 13D5
Siemens E82CC
Mullard 4003
RCA 5814 gray plates
GE 5314a triple mica
EH 12au7
and still havent rolled my other half. I gave up trying to say which tube I like best as im still messing with the amp.

It is getting there..I am guessing a week at most... A bunch of us prototype builders (including myself) are already on the list when the first production boards hit..I understand that kits are being readied for this amp that should make building this little doozy of an amp a breeze.

I can't wait to build my second one..the 12BH7A is a must for this amp.


more pics

That was exactly what I wanted to hear.

How much is the total cost of building one of these beauties?

I can't really comment on that as I do not know honestly. The folks who are working out the details of the kits will reveal all soon enough in at most a week I think).
What I can tell you is that as a prototype builder, it probably cost me about 140$ USD not including tubes. This is for the stock version with only the opamps being changed to Burr Browns. The total also includes the tube rings that are going to arrive by the end of next week...

I am honestly blown away by how good this sounds..I have it playing Diana Krall through my HP-2 yamaha orthos..brilliant. I will post final pics after I install the tube rings.

Can anyone confirm whether 12AT7 tubes will work with this? I have been buying up some 12au7, 12bh7a and 12at7 tubes in preparation for building this amp!

They will work but probably have too much gain Edit: I was wrong about it working but right about too much gain. It's looking like its best to stay < 35mu. I link to runeight's tube compat post from the 2nd post in this thread. There may be a couple number transposes in the thread (8416/8614, 7316/7318 ?) and there may be others added to the list. A nice website consolidating info will be available soon. As well as a way to build this amp With differing levels of bundling options likely.

Edit: WRT keyid's coupling cap experiences - Think preference hits here & everyone was/is happy w/BoM caps, but being tweakers its hard to resist tampering, uh, "improving". A couple of us are using non-Bom couplers (Sonicap Gen II, etc.) to good effect, so keyid's experiences may not be others (& vice versa).

I have not been able to get 12AT7s to work satisfactorily. You will, however, enjoy the rest of your collection.