Doorway Hybrid Integrated (but not really integrated) AMP

The amp has arrived. The speakers are Klipsch Cornwall II. Using the supplied tubes there is a graininess to the sound. I changed the small tubes to the Western Electric 403B tubes. The sound smoothed out pleasantly. You could stop at this point and enjoy this amp. I kept going and added 6v6G output tubes using the adapters. Very holographic now. You can hear the air of the venue where the recording was made. This amplifier is a keeper.
 

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Love the APPJ/MW with the 6V6 Ken-Rads ( short for Kentucky Radio circa 1940's ). The other available adaptor allows use of Tung Sol 6AQ5 tubes, also a very good sounding tube. The stock Chinese tubes that came with this amp were garbage.

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I dont know that you have any, but a bottle to try would be these. JAN 6005W

They are a mil spec ( dur ) 6AQ5 and very nice to listen to, although they take a little time to settle down.

Joe
 

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Funny. I was just perusing this thread early this morning because I still haven’t made up my mind on which direction I’m going to go - hybrid or full tube. Given the cost of the AAPJ, I’m leaning toward giving it a try. That’s how I’m feeling today anyway. May change tomorrow. I may be slow, but I am indecisive.
 
Funny. I was just perusing this thread early this morning because I still haven’t made up my mind on which direction I’m going to go - hybrid or full tube. Given the cost of the AAPJ, I’m leaning toward giving it a try. That’s how I’m feeling today anyway. May change tomorrow. I may be slow, but I am indecisive.
I've been on the fence since seeing @Poultrygeist post his in the past. Do I need another amp? No. Do I have room for another amp? No. Would I like another amp for fun? Hell yes!

I'm plagued by 1st world problems.😐😉
 
Wondering if anybody has had any experience with this.

👎👎 Badly rolled off highs, even after I dumped the crappy tubes, and regardless of speakers used. It quit after two years of 8-10 hour days of use. I got it working, doing the dumb thing (throwing good money after bad) of replacing all the caps. The one power supply cap that killed it was so far out of spec that it wouldn't fire up the unit anymore. All the rest measured at the very bottom of the 20% tolerance range. The new caps didn't improve the sound either, but at least it still worked when I stored it away. Or, mostly worked. One of the EL84s had gotten a little noisy but by that time, it had a lot of hours on it. So, not really a fault of the amp or the tube.

BTW, that rolled-off sound wasn't a fluke. One review I found after the fact (by Ken Rockwell--might have to find it on archive.org) summed up what mine sounded like although, after having torn into it, I disagree on any remark saying this unit was "high quality," especially with the poor quality caps inside and all the other off-brand components I found inside.

I did the sane thing for my situation (after another chi-fi tube amp disappointment) and went with a Sprout100, although I did think about the NAD D3020 (can find those for $350-ish refurbished) or similar small integrated amps with built-in DACs. This was for a desktop system (hence the need for a DAC), so smaller is better. I've got C-J components in my main system, so I have tubes in the house already and I'm good with a different type of amp for the desktop.
 
Had the three tube version for awhile and compared to the four tube model I found it somewhat lacking. It has an entirely different tube set.

This guy has an amazing collection of tube amps is fairly complimentary of the TubeCube.

 
👎👎 Badly rolled off highs, even after I dumped the crappy tubes, and regardless of speakers used. It quit after two years of 8-10 hour days of use. I got it working, doing the dumb thing (throwing good money after bad) of replacing all the caps. The one power supply cap that killed it was so far out of spec that it wouldn't fire up the unit anymore. All the rest measured at the very bottom of the 20% tolerance range. The new caps didn't improve the sound either, but at least it still worked when I stored it away. Or, mostly worked. One of the EL84s had gotten a little noisy but by that time, it had a lot of hours on it. So, not really a fault of the amp or the tube.

BTW, that rolled-off sound wasn't a fluke. One review I found after the fact (by Ken Rockwell--might have to find it on archive.org) summed up what mine sounded like although, after having torn into it, I disagree on any remark saying this unit was "high quality," especially with the poor quality caps inside and all the other off-brand components I found inside.

I did the sane thing for my situation (after another chi-fi tube amp disappointment) and went with a Sprout100, although I did think about the NAD D3020 (can find those for $350-ish refurbished) or similar small integrated amps with built-in DACs. This was for a desktop system (hence the need for a DAC), so smaller is better. I've got C-J components in my main system, so I have tubes in the house already and I'm good with a different type of amp for the desktop.
This isn’t for a desktop system*, but more along the line of something to play with on a limited budget. And with limited space. I have been tempted by the NAD, but was kind of looking to play with something with tubes. Also without tubes this is readily available at a deeply discounted price:


* have active speakers for my desktop
 
Had the three tube version for awhile and compared to the four tube model I found it somewhat lacking. It has an entirely different tube set.
Mine used EL84s and a 12AX7, although I thought I'd seen a version of that three-tube amp a few years ago that came with Russian-numbered tubes. Could be a completely different circuit in the three- vs. four-tube version also.

I wish I had the time to build my own, to be honest. But I'm sitting here with a Grundig tabletop radio that needs its audio circuit refreshed, and an RCA 45-EY-3 I bought 20 years ago with the intention to refurbish, and it still sits collecting dust. 😁 I'm also out of room for any systems other than my main one and my desktop, so I'd have nowhere to use it. But I miss that smell of rosin-core solder...
 
The four tube S1 wasn't a bit out of place powering the ( expensive for me ) Lowthers. To my ears it sounded as good as my Dennis Had EL-84. Still waiting on a Decware amp I ordered in January 2022 and hopeful it will be an upgrade but wouldn't be surprised if it isn't.

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And fairly new to the market is the Dayton Audio HTA100 Integrated Stereo Hybrid Tube Amplifier. Complete with a 5-year warranty.

Hi-Res folks would definitely want to use an external DAC.
Digital Section
Digital Inputs............................................ SPDIF LPCM (up to 48 kHz 16 Bit)
PC-USB........................................................ up to 192 kHz 32 Bit
Bluetooth.................................................... 5.0

 
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Hybrid tube/solid state amps are not the best of both worlds. I had much rather use a good tube preamp with a good solid state amp as I believe it to be less of a compromise. I once owned a Bada hybrid pictured below and found it far less resolving than the less expensive but all tube APPJ/MW. I did love the Bada's looks.

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