Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on March 30, 2020, 10:26:25 am

Title: Merlin Suggestion on PS - Please I need a clarification
Post by: kagliostro on March 30, 2020, 10:26:25 am
Merlin as to avoid in a better way the ripple on B+, suggests, in the case an additional stage of filtering is added, to split the resitor of the filter in the way you can see on the further images

(https://i.imgur.com/sIgMCbI.jpg)

(https://i.imgur.com/MTv2k5d.jpg)

But there is something that escapes to me, in one image you can see the ground connection and in the other there is no ground connection showed

Which will be the correct way to implement such a splitted resistor on the PS regard the ground connection ?

Maybe the bridge connection to the first filter has to be floating ???

(https://i.imgur.com/dFhhiL4.jpg)

Many Thanks

Franco


Title: Re: Merlin Suggestion on PS - Please I need a clarification
Post by: shooter on March 30, 2020, 10:47:57 am
I think it's just an oversight
I also believe the bridge and 1st cap IS above ground by the "additional" dropping resistor.
Title: Re: Merlin Suggestion on PS - Please I need a clarification
Post by: jjasilli on March 30, 2020, 11:49:15 am
My 2009 printing of the Book has only 12 Chapters.  You seem to reference Ch 13 and 15.  From what I see online it looks like Ch 15 is dedicated to Grounding.  Maybe Ch 13 is dedicated to filter circuits, and is not focused on grounding techniques.
Title: Re: Merlin Suggestion on PS - Please I need a clarification
Post by: PRR on March 30, 2020, 12:21:15 pm
> Maybe the bridge rectifier connection to the first filter has to be floating ???

Yes.
Title: Re: Merlin Suggestion on PS - Please I need a clarification
Post by: kagliostro on March 30, 2020, 01:39:53 pm
Grazie shooter - jjasilli - PRR

About chapters .... I really don't remember where I downloaded those images, however I must verify may copy of the High-Fidelity Valve Preamps, may be that there those chapters are present

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> Maybe the bridge rectifier connection to the first filter has to be floating ???

Yes.

Thanks for the replay

Franco


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EDIT: I verified, no, those images aren't in the High-Fidelity Valve Preamps Book, image 15.7 is on Valve Preamps Second Edition (a B&W image, color image is only on the web) and no trace of the 13.11 image (????)