The "Opus" Amp??

[TIMBO]

http://www.el34world.com/Forum/index.php?topic=7737.msg68888#msg68888

Does anyone know if this was successful as i was wanting something like this.  Is there a PI , Power amp and PSU to go with it. If not could anyone post a good 6L6 power amp with VVR. Thanks

[Geezer]

Still going to build it, but have been too busy with other (non-amp) projects......

It is the HoSo preamp (chnl A) combined with the Dumble type "d'lite" preamp (chnl B).

I will look to see if the poweramp section has been posted....can't remember. However, even if it has, it will need to be tweaked (B+ rail & such) when it actually gets up & running.

Geez'r

[Geezer]

Here it is>>>>>

[tubenit]

could anyone post a good 6L6 power amp with VVR

My T-Lite fits that description. Look in the SCH files.

Tubenit

[TIMBO]

I was considering the CBR as a build and rembered the channel switching post.I was wondering if the A/B switch could be added to the CBR schem just before the reverb and keeping the power amp and VVR as per the schem

[TIMBO]

HI guys , Ive been playing around with a few things and came up with MY Amp .The only thing i'm not sure of is the preamp voltages. Help needed, Thanks http://s761.photobucket.com/albums/xx254/Timbo-08/18w/MY%20AMP/

[Geezer]

Circuit pics posted here (for more possible help & comments/easier viewing)

[Geezer]

more..........

[Geezer]

My goodness! Beautiful drawings  ........did you know there's a free program to do them in so that they are editable & easy for others to post suggested changes?


Look here for the free download>>
http://www.el34world.com/Forum/index.php?topic=500.0

[tubenit]

DaGeezer directed you to a free SCH download which allows you to draw and edit a schematic or layout at will.

I've given you a jump start on your amp schematic and there is already an OPUS layout that I drew which you should be able to easily adapt for your "My Amp".  You will need to finish the preamp to CF section on the EF86 channel.

Please note you can save large sections of the schematic as a custom component. For example, I took all the D'Lite preamp and overdrive section and saved it as a component and them added to CBR 5879 schematic which I begin editing to match your schematic.

With respect, Tubenit

[TIMBO]

Thanks for the headsup.I did have the program Jschem but didn't take the time to give it ago. :smiley:I played around with your program and came up with this schem. I've circled the Brite switch because i'm thinking its overkill as this part is from the Vox AC15 So maybe i could add another switch ( like it needs another switch) to switch between it and the tone stack(thoughts!!).All the rest is much the same.I did notice some changes to the PSU. Has the voltages been calculated? If not how do i calculate voltages for each stages of the amp(simple form)Also i canont take credit for this schem.So if i can get this to fly i would like call it "MY OPUS" if that OK :grin:Thanks                                                                   

[TIMBO]

http://s761.photobucket.com/albums/xx254/Timbo-08/?action=view&current=MYOPUSV10BassBriteSW.jpg&newest=1                                                             http://s761.photobucket.com/albums/xx254/Timbo-08/?action=view&current=MYOPUSV10ToneSwitch.jpg

[TIMBO]

Can anyone give me some feedback on this project.

[tubenit]

This is feedback on how I would approach it not advice on how you should.  I would keep the EF86 channel simpler. It's already a very complicated amp and build. In fact, I would personally use the 5879 which does not seem to be quite as microphonic as I hear reports of the EF86.

As far as the B+ rail ......... I just make guesses by looking at other amps that at some level look similar and experiment alot.  I found I like 150-160v on 12AX7 plates and on 5879 tubes, I like it in the 130-140v range. I make a best guess and test voltages and adjust. Why not try the B+ rail as is shown on the schematic and then adjust?

I like using rectifier tubes that are interchangeable because it does offer easy changes in the tone or responsiveness of an amp such as 5Y3GT, 5V4 and GZ34 tubes.  I personally would not use the EZ81. The interchangeable rectifier tubes can help with the B+ rail voltages also.

How you construct the layout will be critical to the build. Oscillation problems on this build could be easily a problem on this build, I would guess? 

With respect, Tubenit

[TIMBO]

Thanks tubenit, I like the way you think.When searching for this build i did study lots of schems . So i will start to put it together in a way that will allow me to make changes. Not having training in this field i am a little caurious when it comes to what i can and can't do. When i renovate old houses the possibilities are endless i fined the same with valve amps Thanks

[TIMBO]

HI Guys , Its been awhile. All is going well getting it to fit in the chassis. But before i proceed further could you guys check the schem .thanks

[TIMBO]

Some pics

[TIMBO]

and more

[TIMBO]

Voltages:-  P1       P2       P3       P4      P5       P6        P7       P8       P9
   V1          -112         0       -1.7                      -112         0       -1.7     .64
   V2        - 133       0        -1.27                    -227     -133    -139
   V3        -122      .356      -1.04                    -119     .001     -1.15
   V4        -125         0        -1.3                     -137       0        -1.27
   V5         - 346       0        -2.57                    -112     -127     -1.18
   V6         - 245    - 23        -66                      -235         -23      -66
   V7                                - 325    -386   - .02                           -33.8
   V8                                 -387    -386   - .02                           - 33.8
   V9            -430
When taking the readings my multimeter was showing that the readings were in the negitive???The amp startedup fine with the "A" channel not sounding too good(very low volume with VVR to the max and then fading off to nothing alot farting and crackling) Switching to "B" channel very good  sound  NO HUM (only when Gain and Master are to the max, Overdrive sounds great and VVR works well. GZ43 produces 430v at the standby switch and 392v at A. VVR range 38v-392v but does affect D and E by 10v when turn to max, Any thoughts Thanks