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Hoffman Amps Forum image Author Topic: It's raining here.......  (Read 42779 times)

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Offline jazbo8

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Re: It's raining here.......
« Reply #150 on: May 23, 2014, 03:31:39 am »
I see you have been busy... Based on the new voltage readings, here are the load lines for the 8 Ohms & 24 Ohms loads for your consieration. I also had a question, when you said the plate jumped to 100mA, was that the reading across the cathode resistor? Ditto for the 20mA? I think if you are less interested in getting the maximum output power like Marshall, and prefer reliability, then you need to re-configure the output stage's operating condition (see bottom chart), unless of course, by doing so, it ruins "the tone"... Also, BTW, Aiken mentioned that certain models of the Marshall 100W amps were well known tube eaters, so I would not bet on the EL34's longevity, especially not with the current production tubes.




A very conservative scenario:

« Last Edit: May 23, 2014, 03:38:55 am by jazbo8 »

Offline SILVERGUN

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Re: It's raining here.......
« Reply #151 on: May 23, 2014, 08:21:55 am »
Based on the new voltage readings, here are the load lines for the 8 Ohms & 24 Ohms loads for your consieration. I also had a question, when you said the plate jumped to 100mA, was that the reading across the cathode resistor? Ditto for the 20mA?
Thanks for taking the time to do that...I was very curious how to how they would look..
And, yes,, I was taking the current readings across the 1ohm cathode resistor,,, only.

So in your very conservative example, I see RL=7.2K which makes it easy for me to get there by just doubling the load on the secondary...
What does the line look like if I just stay at 460V plates, but use a 8 ohm load on the 4 ohm tap to reflect 7.2K on the primary?

I think if you are less interested in getting the maximum output power like Marshall, and prefer reliability, then you need to re-configure the output stage's operating condition (see bottom chart), unless of course, by doing so, it ruins "the tone"... 
There's one thing I need to change about what I said last night....
When I plugged the 16ohm speaker cab into the 8ohm tap I reported that some of the "tone" had been lost,,,but I had accidently switched to my rhythm (neck single coil) pickup and didn't know it,,,, I didn't notice until I plugged in a new set of tubes and was trying to figure out where the tone had gone...
So I was mis-judging the resulting tone of the impedance mis-match with the wrong pickup selection......

I will try that again tonight, and try to give more accurate, subjective reports of TONE


Offline jazbo8

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Re: It's raining here.......
« Reply #152 on: May 23, 2014, 09:00:42 am »
So in your very conservative example, I see RL=7.2K which makes it easy for me to get there by just doubling the load on the secondary...
What does the line look like if I just stay at 460V plates, but use a 8 ohm load on the 4 ohm tap to reflect 7.2K on the primary?
You got it, 8 Ohms on the 4 Ohms tap or 16 Ohms on the 8 Ohms tap will give you the 7.2k primary load. The chart would look the same.
Quote
I didn't notice until I plugged in a new set of tubes and was trying to figure out where the tone had gone...
So I was mis-judging the resulting tone of the impedance mis-match with the wrong pickup selection......
I will try that again tonight, and try to give more accurate, subjective reports of TONE
Cool, let's see if the tone is still acceptable with the higher load.
« Last Edit: May 23, 2014, 09:02:53 am by jazbo8 »

Offline SILVERGUN

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Re: It's raining here.......
« Reply #153 on: May 30, 2014, 02:00:30 pm »
Cool, let's see if the tone is still acceptable with the higher load.
Jaz,
I was hoping to have a good solid answer for you , but I don't...
Part of the problem is that when I switch to the 16 ohm load it is a Marshall bottom cab (loaner) that has 4 G12T-75's, and I don't like the way it sounds any other time anyway.....so it does change the tone and it clouds my results (which are mostly my subjective opinion anyway)
Sooo,,,I did notice a change in tone that was not desirable with the higher load.....maybe thinner and with less "zip"

And since I liked it so much the other way...I decided to install the bucking xfmr and be done with it....plate V is down in the 460's now (depending on bias) and it just sounds phenomenal, so I'm done F'in with it..  for right now.

I've got to get the cosmetics in order. :sad:

Offline SILVERGUN

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Re: It's raining here.......
« Reply #154 on: May 30, 2014, 02:44:59 pm »
The girl wanted to hear her amp, so I put a big push on this past Sat. and took it in to her....
Here's a couple pics of the amp, with it's temporary 'prototype' graphics,,,which I'm sure you guys will get a kick out of.
It felt strange to take it out of my shop, and it made me a little nervous to realize that I wasn't going to be able to travel with it.  :wink:

It received the highest of marks from her and her co-workers, and she absolutely loved the sound,,,and thinks she might want another one  :huh: :BangHead:....the coolest thing she said was:
"It sounds better than the Blackstar or the Marshall DSL I was looking at"  :happy1:
That was all I needed to know.

The grill cloth was tight when I installed it, and I'm pretty sure that the wind coming off the speakers is what stretched it out and made it saggy... :huh:

After the big push, I took the week off, because the due date has been moved back to late July,,,and I just had to get away from it for a couple days.

Here's a link to a short clip of the amp with the gain maxxed out and a couple slightly different tone settings, including the mid-scooped "metal" tone...
The clip is just to demonstrate the brutality of the available gain,,,,but I found some better settings with the input gain rolled back.
Excuse #2---the sound quality is poor due to the fact that I can't get the recorder too close to it without overloading the input....it is what it is:

http://www.soundclick.com/player/single_player.cfm?songid=12806552&q=hi

Offline Ritchie200

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Re: It's raining here.......
« Reply #155 on: May 30, 2014, 04:51:04 pm »
THAT is AWESONE!  You should be super proud of this beast!  Once the word gets out, you will be busy for months - years!  It would be cool to get a recording of her using it in a live setting - to see how it cuts through the mix.  I'm sure it will do fine!  Well done, well done indeed!

Jim

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Can we have everything louder than everything else?

Offline SILVERGUN

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Re: It's raining here.......
« Reply #156 on: May 30, 2014, 04:55:27 pm »
THAT is AWESONE!  You should be super proud of this beast!  Once the word gets out, you will be busy for months - years!  It would be cool to get a recording of her using it in a live setting - to see how it cuts through the mix.  I'm sure it will do fine!  Well done, well done indeed!
THANKS MAN!
That's the most POSITIVE thing you've ever said to me so I had to quote it just in case you edit it out,,,it will live forever with this thread  :l2:

 :occasion14:

I was thinking of doing it in a head format, right now, while it's all still fresh in my head....any more reviews like that and I'm gonna have'ta...

Offline Willabe

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Re: It's raining here.......
« Reply #157 on: May 30, 2014, 05:01:25 pm »
Well it looks great and I'll take your word that it sounds great too.

Well Done!



                  Brad      :bravo1:

Offline SILVERGUN

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Re: It's raining here.......
« Reply #158 on: May 30, 2014, 05:05:22 pm »
I'll take your word that it sounds great too.
Now THAT's funny  :l2:


Offline Willabe

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Re: It's raining here.......
« Reply #159 on: May 30, 2014, 05:08:01 pm »
I'm sorry that didn't come out right.     :BangHead:

I know it sounds great!


              Brad     :w2:




Offline TIMBO

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Re: It's raining here.......
« Reply #160 on: May 30, 2014, 05:11:48 pm »
Top marks SG, Keep up the good work. AWSOME

Offline SILVERGUN

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Re: It's raining here.......
« Reply #161 on: May 30, 2014, 05:18:27 pm »
Top marks SG, Keep up the good work. AWSOME
Thanks TIMBO!
I'm gonna work on a better clip, because I really don't think this does it justice....I just had to put something up so I didn't keep you guys waiting

In person it's just brutal and has a great, tight, controllable feel.....it sounds incredible with EMG's

The clip is with the gain all the way up, just to demonstrate the far end....at 3-5 it's not such a bee-hive  :icon_biggrin:

Offline jazbo8

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Re: It's raining here.......
« Reply #162 on: May 31, 2014, 01:10:28 am »
Man, it's really got the in-your-face attitude down, well suited for the type of music she is playing, so that's what counts. As for the higher load not sounding as good, I am not surprised, as that's part of the Marshall tone - the pretty load line doesn't mean a thing if it sounds bad  :icon_biggrin:  Great work, looking forward to hear more clips of the beast with improved recording...

Offline lego4040

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Re: It's raining here.......
« Reply #163 on: June 01, 2014, 09:42:11 am »
That is killer SG, and molded after the greatest metal amps combined. So many great metal guitarists out there I can only imagine how many amps you looked at. If you can go from Micheal Schenker to Dimebag in one amp I'm sold :icon_biggrin:

Offline Stankfut

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Re: It's raining here.......
« Reply #164 on: June 02, 2014, 02:10:57 pm »
That sounds really impressive! Congrats, I think its a winner!

Offline sluckey

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Re: It's raining here.......
« Reply #165 on: June 02, 2014, 02:53:26 pm »
That really turned out great. Good looks and good sound. And we know who she'll be calling on when she needs a tune-up.   :wink:
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline Tone Junkie

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Re: It's raining here.......
« Reply #166 on: June 02, 2014, 06:43:22 pm »
Gotta love an amp that just reaches out and grabs ya.  :guitar1
Bill

Offline SILVERGUN

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Re: It's raining here.......
« Reply #167 on: June 02, 2014, 06:52:38 pm »
Well thanks again guys, I really appreciate all of the positive comments....it appears that my week off is turning into a week and a half.  :icon_biggrin:
There's still plenty to do and I'm looking forward to getting back to it and cleaning up a couple things, including a new back panel and faceplate, re-stretching the grill cloth, and some slight troubleshooting.

I'm also considering taking it into a local studio to get a real demo....it deserves it.
I'm still working on page 2 of the schematic, and I already have one slight revision to make on page 1.

Here's a pic I snapped when we were in the isolation booth trying it out....I covered her face for her privacy, but you get the idea...
She's giving us the universal metal sign for "IT ROCKS!"

And we know who she'll be calling on when she needs a tune-up.   :wink:
The scary part is she's moving away and taking it with her,,,,,so I'm gonna add one of those 'message in a bottle' type care packages that TIMBO brought up recently including contact info. for me, a schematic, and explanation of the design.

Offline SILVERGUN

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Re: It's raining here.......
« Reply #168 on: June 02, 2014, 07:00:54 pm »
Gotta love an amp that just reaches out and grabs ya.  :guitar1
Bill
I knew you'd appreciate this one TJ.
It's got this great low end growl to it that I can't get enough of.

It would be cool to get a recording of her using it in a live setting - to see how it cuts through the mix. 
Unfortunately, that's not gonna happen.....
But, funny thing is,,,I don't think she really wants it to cut through....she's a solid rhythm guitarist and she wanted me to build it purposefully less bright than the Sovtek (which she tried)
When we were demo'ing it, I kept turning up the treble, and she kept turning it back down.....
Maybe that's got something to do with me losing some of my high freq. hearing?  :icon_biggrin:

Her request was more gain and more bass.........she got it.

It would be very easy to bring back some highs with just a few small changes to the schematic.

Offline Stankfut

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Re: It's raining here.......
« Reply #169 on: June 03, 2014, 11:44:47 am »
That really turned out great. Good looks and good sound. And we know who she'll be calling on when she needs a tune-up.   :wink:


Okay, so what about when the amp needs a tune up? :wink:


On a serious note, its a shame she's moving away and you won't get to hear it in person. I would love to build someone an amp and hear it used as intended, not just my hack playing!




Offline Ed_Chambley

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Re: It's raining here.......
« Reply #170 on: June 03, 2014, 11:57:56 am »
That thing rocks.  Why didn't you do a demo of the high gain channel? :l2:


Great job, really.  You know everyone likes different things, but in the high gain territory this thing is really nice.  Love the way you can still hear all the notes in the chords and the squeaks and grunts.


Did it end up being fairly quiet when idle?


Maybe a studio recording would do justice, but what an amp sounds like live is much different than a studio produces.  The demo is great and I can tell what it sounds like.

Offline SILVERGUN

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Re: It's raining here.......
« Reply #171 on: June 03, 2014, 01:02:46 pm »
That thing rocks.  Why didn't you do a demo of the high gain channel? :l2:
:l2:
You know ME  :icon_biggrin:.....there is still more to showcase, but I had to get a way from it for a while...you know how that is

Great job, really.  You know everyone likes different things, but in the high gain territory this thing is really nice.  Love the way you can still hear all the notes in the chords and the squeaks and grunts.
I think so too....I think it's a great type of super-high gain style that guys don't usually build, because the market covers most of the bases...
I was hoping that the clarity would come through a little better...
One improvement was subbing in a 12AT7 in the PI in place of the 12AX7 I initially had in there....it brought out definition and clarity and got rid of some buzz....was a keeper, and I used a JAN Phillips NOS there

Did it end up being fairly quiet when idle?
Yes, and that was one of my biggest concerns with stuffing this all in there....I want to believe that the separate power supply and separate power board had something to do with it,,,,but my buddy that helps me with play testing/tweaking was very surprised with the low noise...it does hum/hiss, but nowhere near what it could if it was poorly made...

Maybe a studio recording would do justice, but what an amp sounds like live is much different than a studio produces.  The demo is great and I can tell what it sounds like.
Yeah,,,I was just hoping that they would have some better equipment that would be capable of harnessing the power...I have the input vol. on my little field recorder on 7 (out of 100) and it still clips...I don't like the demo clip, but it's all I've got so far.

But you're one of the guys that I was worried about,,,so if you say it's good, then it's good.  :thumbsup:

Offline Ritchie200

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Re: It's raining here.......
« Reply #172 on: June 03, 2014, 10:01:47 pm »
So what are we?!?!?!  Chopped liver?

Wow.....that is positively the last time I am positive about anything remotely positive that may surround your negatively biased aura - and I am positive about that... :lipsrsealed:

Thanks a lot ex-pal... :m13

Jim

My religion? I'm a Cathode Follower!
Can we have everything louder than everything else?

Offline SILVERGUN

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Re: It's raining here.......
« Reply #173 on: June 04, 2014, 09:40:26 am »
But you're one of the guys that I was worried about,,,so if you say it's good, then it's good. 

So what are we?!?!?!  Chopped liver?
Don't be so sensitive....there's no place for that here...this isn't the Oprah Forum!
Who's to say you weren't on the list?

I'm pretty sure Ed can hear the difference between 2 gnat farts at 100 yards ....that's what makes his opinion matter to me....if he would have PM'd me and said "Yo man, that sounds like crap,,,what are you smokin' up there?",,,I would've tried again. If you would've said it, it would've been Jim being Jim.

Me and you suffer form the same 1K ringing that makes us not be able to differentiate between a plane flying overhead and someone flushing a toilet upstairs.....so when you say it's good, it's no different than being told that the sound of a train coming to a screeching halt is pleasant.
Get over yourself!.....sheeesh   :rolleyes:

Thanks a lot ex-pal...
Well that was not surprisingly,, short-lived
And you have earned yourself a new nickname :  CL       (Chopped Liver)
Which is, again, not-surprisingly,, the opposite of LC.
So as kind, caring, considerate, funny, talented, handsome, intelligent, honest, and just an all around great guy that I am....(I know this because it says so on my birthday cards every year)
You sir, are the opposite.



Offline Ritchie200

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Re: It's raining here.......
« Reply #174 on: June 04, 2014, 10:00:49 am »
Hey, I've heard some very melodic screeching train stops - so there!

As far as the toilets flushing, plane overhead, 1K ringing....  Are you talking about a Tele?

What ARE you smoken up there?  Hey, I'm still trying to be positive here!

CL :m8

My religion? I'm a Cathode Follower!
Can we have everything louder than everything else?

Offline super&plexi

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Re: It's raining here.......
« Reply #175 on: June 04, 2014, 03:29:28 pm »
Great to watch the build progress.   Also very cool to see the input/interest from the very learned seasoned builders  to the newly interested.     With all of the different trades that are here has anyone come up with anything like using pipe conduit and stuff like that. My first build was a take on that because I saw so many Supros-those split chassis little hot rod jobs.     
 
 This build of yours mirrors very closely what I would like to have as my next project. I'm a big fan of the tone only knob.   Being a big fan of pedals, having a boss heavy metal pedal with the concentric knobs, the odd 1,2,3 tube screamer all set differently,  od of choice...fuzz...all flavors of gain would be there.

But gigging, and pedals are growing tiresome-not the playing, but hauling my own rig. Hauling a small amp, with all the gain  I'd ever need and being able to turn up or down from just my volume on my guitar is becoming extremely attractive.
All my friends are from N.Y. and Rangers are spoken...especially Hendrick Lundquist if you're talking to my girl Jeanette.

 This move has been really tiresome, and having all my stuff from the shop all boxed up- some in the old storage some in new storage and some at the new place is almost de-moralizing...but its a ray of light to live  my amp building life vicariously through yours. Keep it up...The Gain, that is.

.
keep on with those scales and that fish is gonna die, if it don't bite you first!

never fried a tranny ..till I built a dim bulb tester. UPDATE-haven't fried anything since learning how to properly build & use one...thanks Uncle Doug, & el34 World

 


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