Can you elaborate on why this is important?
I would love to build an amp someday (even a copy), and I feel like I have a pretty strong knowledge base.
Wolfe Amplification Hellfire- Have a quick listen
- Thread starter Wolfeman
- Start date
Can you elaborate on why this is important?
I would love to build an amp someday (even a copy), and I feel like I have a pretty strong knowledge base.
The tone stack needs sucks the life out of the signal. Sometimes as much as 20db can be lost. since the tone stack messes with the frequency, impedance plays a big role in how it reacts. A cathode follower can drive the tone stack with its very low output impedance, hence why they are favored in a lot of amps. Sometimes a tube buffer after the loop is implemented. Sometimes strange driver stages are used, like in the 5150, that I still don't understand. Some amps have the tone stack right after the input stage, where its easy to implement.
All this becomes much more difficult when you have lots of cascaded gainstages. Somehow I managed to make a 6 gainstage amp that drives the tonestack fine. No crazy CF or buffers used. I will say that the tone stack really likes it when the FX loop gets activated, it must be acting as a buffer so you get a little boost.
There is a lot more too it, but you get the idea. Best thing to do is read a lot of books, like the Kevin O'Connor TUT series, Merlin Blencowe's preamp book is great, and all the richard Kuehnel stuff is good.
All this becomes much more difficult when you have lots of cascaded gainstages. Somehow I managed to make a 6 gainstage amp that drives the tonestack fine. No crazy CF or buffers used. I will say that the tone stack really likes it when the FX loop gets activated, it must be acting as a buffer so you get a little boost.
There is a lot more too it, but you get the idea. Best thing to do is read a lot of books, like the Kevin O'Connor TUT series, Merlin Blencowe's preamp book is great, and all the richard Kuehnel stuff is good.
And if you are ready to build, then I say go for it. Start off with a ax84, they have step by step guides and they are really cheap to build, and they actually sound cool. Then move up to an SLOclone to learn all about high gain, it a whole different ball game when lead dress and component placement come in to play.
jangoux
Member
- May 9, 2006
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Did you user the regualr ´Marshall´ tonestack or went for something different? I was going to build a Tiny Terror and to avoid the 20db loss, i decided to go active, and ended up designing (with a good help from Joey from SLOclone´s) a very cool lossless active SS EQ system, but have yet to find time to build it.
Wow, thanks for the tips on the ax84 and SLO clone. It looks pretty easy.
As soon as I get $250, I know what my next project is...
Trent
TravisW
Member
AX84 is a great site. I started a Firefly 3 years ago that I still need to finish. The clip sounds pretty good, esp for not having a lot of volume behind it.
Man. Thanks for this. I am so stoked. I know its a little cheating, but I went ahead and ordered the PCBs for the SLOclone (two sets). I am going to build two amps at once. I like doing things in pairs. I have lots of great industrial supply stores around that often have great components for cheap...so I plan on building them depending on what parts I get, so it would be interested to see how different they sound with different trannys etc.
From my sloclone builds, i can tell you that transformers(output) make a HUGE difference in how your amp will sound. They are kinda the 'life' of the power amp. In one of my builds I have a cheapo $50 OT, and it sounds better than my hammonds and MM ones.
Yeah it's a standard Marshall with a few different values and a contour knob.
I was thinking about using a baxandall at the end chain, with a mid knob out after the input stage, but I couldn't get it to react the way I wanted it too. I'd love to try out an active TS, I loved the eq control on the XXX/JSX
Sorry that I haven't gotten any more clips together. I made a bunch of changes due to some requests.
I eliminated a control I had for the power amp, which was a toggle that would change between 2 different high pass options. I ditched it since the only people that would hear a difference would be 8 string players or bass players. Why put a useless feature in there.
The higher gain path now has more gain, since it was asked for. I actually like it better now, since doing the mods tightened up the low end, and makes it sound much more different from my 'xtc' type path.
I'm now working out an issue with the FX loop. For some reason, it is acting funny when turning it on- the level cuts drastically or boosts drastically, depending on the loop setting. It worked fine before, so something I did messed with the levels going into the loop buffer. I have to run it through Spice some more and make some adjustments to get it perfect. It's still a transparent loop, it just isn't acting the way I'd like it too. I might switch to a mosfet loop instead, we will see.
Added a 'sag' control to simulate a loaded rectifier tube. Kinda adds a nice touch, since my power supply was really tight, so some may like this.
Just registered my domain at http://www.wolfeamplification.com. I'm going to have to find someone to build the site, since I will never have the time to get it done.
Things are coming along!
I eliminated a control I had for the power amp, which was a toggle that would change between 2 different high pass options. I ditched it since the only people that would hear a difference would be 8 string players or bass players. Why put a useless feature in there.
The higher gain path now has more gain, since it was asked for. I actually like it better now, since doing the mods tightened up the low end, and makes it sound much more different from my 'xtc' type path.
I'm now working out an issue with the FX loop. For some reason, it is acting funny when turning it on- the level cuts drastically or boosts drastically, depending on the loop setting. It worked fine before, so something I did messed with the levels going into the loop buffer. I have to run it through Spice some more and make some adjustments to get it perfect. It's still a transparent loop, it just isn't acting the way I'd like it too. I might switch to a mosfet loop instead, we will see.
Added a 'sag' control to simulate a loaded rectifier tube. Kinda adds a nice touch, since my power supply was really tight, so some may like this.
Just registered my domain at http://www.wolfeamplification.com. I'm going to have to find someone to build the site, since I will never have the time to get it done.
Things are coming along!
Loop is now fixed, just had the +4/-10 switch wired backwards so it was boosting when it should have been cutting. Easy fix, loop now has the same level going out as going in.
Decided to keep the power amp filter switch. it only affects frequencies from 80-200hz when I run the scope on it, and isn't terribly noticeable when the switched is flipped, but with heavy bass settings and a detunned guitar it does make some difference. Can't really hear it in the room, but with a mic on it it may be useful, and this amp was made for the studio.
Gotta start cutting the circuit boards and pop some turrets in it. This stuff is sexy, even though no one will ever see it unless working on the amp-
Decided to keep the power amp filter switch. it only affects frequencies from 80-200hz when I run the scope on it, and isn't terribly noticeable when the switched is flipped, but with heavy bass settings and a detunned guitar it does make some difference. Can't really hear it in the room, but with a mic on it it may be useful, and this amp was made for the studio.
Gotta start cutting the circuit boards and pop some turrets in it. This stuff is sexy, even though no one will ever see it unless working on the amp-
GeertSamuel
Member
I'm really curious to the design of the amp! Sample sound like it has a lot of potential!
btw. Check your PM!
btw. Check your PM!
iekobrid
Authorized XSr Dealer
JeffTD
Senhor Testiculo
My only question is: who will be the first to play a Stinnett thru a Wolfe ?
Me, via reamping!
But seriously, I'm really interested in this if it can do a 5150 + other type tones in one box kinda deal.
You guys are going to love the mid contour/sweep knob. I got it to shift the mid range from 5k all the way down to 200hz. TONS of tonal options with this knob! and depending on where you set the shift at, it completely changes how the tone knobs react to frequency. I went a different route than Krank did on this- they just have a pot installed across the tone stack where the slope resistor would be. I have a set resistor, a cap, and then the pot, which seems to yield better results(and keeps DC off the pot, so no scratchiness!)
I love this amp haha. I'm not going to want to send this one away. Once I start making profit, I'm going to make sure I build myself one.
I love this amp haha. I'm not going to want to send this one away. Once I start making profit, I'm going to make sure I build myself one.
Bromigo
Member
- Oct 17, 2009
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Just saying, and I am sure that you know this, but there are TONS of amps that have no CF. ADA MP-1, ENGL 530, all Splawns, ect.
I'd be interested in seeing a schematic, just to look at what you've done, but for obvious reasons I can understand why you wouldn't release anything like that. Sounds great man, keep tweaking!
True, but most can't run a standard Marshall at the end of cascaded gain stages without some kind of buffer behind it. I haven't seen the schematics for any of the amps you mentioned though, so I should probably bite my tounge.
Buy one of my amps and you are more than welcome to map it out
