Akai M-8 R2R SE pentode amplifiers

Good thread there, ABMOGGY. :yes: I still can't get over how loud & powerful 3 or 4 watts of tube power is, with the right speakers, and still sound so good. :music: I have lots of learning & experimenting to do yet with tubes, but so far, this is the sweet spot. :yes:
 
ABMOGGY said:
I just think that if the music sounds good, it sounds good regardless of if it's flea SET, P-P, Class-A, B, Triode, Tetrode, Pent, blah, blah, or for that matter chip and Class-D. They each sounds good in their own way.

Happy listening! :music:
Click to expand...

AMEN BROTHER :thmbsp:
 
Rex Everything said:
Post # 9 above shows the mods for using just as a power amp and not the mic pre mods.
Click to expand...


Sorry super old thread, but i'm new here from the Dominican Republic, looking to use the Akai M8 as a Mic Pre, so maybe ya'll can help me out a bit.. So post #9 it's about converting the akai/roberts into a power amp? not a MIC pre, I'm confused:worried: all clarifications are greatly appreciated
 
Has anyone done any of these as far as stand alone power amp? I've got some that the output TXs have endbells and some that don't?:scratch2:
 
Jay I was useing a pair for some time as a bed room system and they sounded good,
I sold them up at your place i think the first time i went.
 
markus said:
try this on for size LToro :D

http://beyondsanityproductions.com/index.php?option=com_content&task=view&id=13&Itemid=28

I'm pretty sure this is the article you're looking for . . .
Click to expand...

Size those matter Markus, hey thanks !! great link Markus, a little complicated for a newbie like me, but my old man says he'll help; However the mod in this thread is super easy, i'm still confused as to for what type of amp is this modification designed for... below there's a portion of the link provided by -tracker X- (post #9) maybe somebody can still help me, i'm a tape op reader, i love the links but again the modification suggested in this thread is very easy to do, again is this modification designed for a mic preamp ?

(tracker X) " If you are using the amps solely as line level preamp/amplifiers, or using
also as high gain microphone pre/power amps this might help:
1. The configuration your using is suitable for non-critical HiFi use.
However for use as stand alone monophonic amps (dedicated for use only as
mic preamplifiers, and stereo line level input power amps) with true flat
bandwidth audiophile response, noise floor levels, and even more dynamic
headroom the following modification should be performed "
 
i've done this with 4 different akai amps.

one was used as a low power guitar amp. still using it on sundays with my acoustic guitar.

two i've used as a stereo amp.

last one is sitting in my closet waiting to be turned into a mic pre one day.
 
I bought an M-8 yesterday. How do you get the amps out of the case? I think I'm going to have to get to the bottom amp as the 3rd tube from the left and the tube socket seem to be missing. If I can fix that I'm going to listen to it as is and try to work up the courage to get into the work in post #9.
 
Please let me know how you do! I was wrong about missing a tube. AK member sloober says that's for biasing the tape recorder. So I'm going to plug a source in and give it a whirl!
 
I just recapped 2 more M8 units last night. Here is a list of caps needed. There are a couple others I didn't have, but these are the main ones. Parts for one monoblock.
4-20uFx25v (used 25x50v)
4- .01uFx600v
2-.02ufx600v
20uFx350v (used 22uFx450v)
20uFx20uFx400v (used 2- 22uFx450v)

John
 
roberts 770 as phono preamps?

Hi,

I am a rookie diy'er who completed the 2 pre's in 1 mod (from beyondsanity productions.com attached below) using the ef86 section and the 12ax7 sections as separate mic pres. I currently am using an external input transformer box for balanced mic operation. I am doing less recording and am interested in using these as phono pres/amps. Any suggestions on achieving the proper impedance and RIAA eq? (currently the 12ax7 input is without the 3.3uf input cap to grid indicated on the attached schematic... maybe part of the problem?)

Running the turntable through the into the 12ax7 stages is slightly harsh and missing bottom end.... (If I am playing a cd through this chain, they sound incredible though I have to turn the volume of the interface very low...)

Chaining the ef86 stage into the 12ax7 stage is worse and causes oscillations.

or, any suggestions on where to look for resources on this application?

Thanks!
 

Attachments

  • Akai M7 Right Schematic _MOD_2_Preamps_In_One.jpg
    Akai M7 Right Schematic _MOD_2_Preamps_In_One.jpg
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Just bought a Roberts 720 today, so I guess I'm on the bandwagon. It's in very nice cosmetic condition but I'll wait until I get the amps restored before I power on. The seller said it's been used recently and worked fine, but I'm not taking any chances.

John
 
turntable with mono blocks?

SteveBOmaha said:
Hi,

I am a rookie diy'er who completed the 2 pre's in 1 mod (from beyondsanity productions.com attached below) using the ef86 section and the 12ax7 sections as separate mic pres. I currently am using an external input transformer box for balanced mic operation. I am doing less recording and am interested in using these as phono pres/amps. Any suggestions on achieving the proper impedance and RIAA eq? (currently the 12ax7 input is without the 3.3uf input cap to grid indicated on the attached schematic... maybe part of the problem?)

Running the turntable through the into the 12ax7 stages is slightly harsh and missing bottom end.... (If I am playing a cd through this chain, they sound incredible though I have to turn the volume of the interface very low...)

Chaining the ef86 stage into the 12ax7 stage is worse and causes oscillations.

or, any suggestions on where to look for resources on this application?

Thanks!
Click to expand...


this is a terrific thread that i'm watching with great interest.

I too have a pair of the akai's that i need to mod.

my thinking was to use these in a turntable only system as well.

I think you may have to run the tt into a phono stage first then to the preamps.

This should resolve the problem with the loss at the bottom end.

the amps work well with line level inputs. (CD, tape, ipod etc...)

Someone who knows more then i do (pretty much anyone) please correct me if i am wrong.

art
 
For phono use you would need an external phono stage I would think. You really don't need to do all that much mod wise to use for hifi. They do make for quite the nice little monoblock system. John
 
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