A couple of my combos I’ve built:

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Doxie man
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A couple of my combos I’ve built:

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One 6V6S powered high gain and one EL84 Lite. Both 18W output with Heyboer & Hammond transformers 😉
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geoff 1965
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Re: A couple of my combos I’ve built:

Post by geoff 1965 »

can't focus the zoom pic,what value is the bias cap on those 6V6's?
i have a high gain 6V6 project amp cathode biased at 330R the same as yours and currently have 1000uf but still experimenting with that.
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Doxie man
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Re: A couple of my combos I’ve built:

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geoff 1965 wrote:
Sat 08/28/21 9:28 pm
can't focus the zoom pic,what value is the bias cap on those 6V6's?
i have a high gain 6V6 project amp cathode biased at 330R the same as yours and currently have 1000uf but still experimenting with that.
330R is what I have in there. Get rid of the ridiculous 1000uf bias cap. Throw a 25-47uf in there in its place. I don’t know why people put those huge caps in the bias circuit. Tune the amp from the first gain stage working your way back to the power section. You’ll find better results that way…..no offense intended. Remember that the higher the gain build, the more you have to pay close attention to low frequencies and high frequencies in the preamp. In short keep the preamp lean and fatten things up later in the circuit.
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geoff 1965
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Re: A couple of my combos I’ve built:

Post by geoff 1965 »

No offence taken! I appreciate your response,so is the F&T bias cap 33uf in yours?
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Doxie man
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Re: A couple of my combos I’ve built:

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geoff 1965 wrote:
Sat 08/28/21 9:48 pm
No offence taken! I appreciate your response,so is the F&T bias cap 33uf in yours?
Yep 👍. I never go above a 47uf. 99% of the time it’s a 25-33 in there
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geoff 1965
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Re: A couple of my combos I’ve built:

Post by geoff 1965 »

Thanks,the power section is the lite 6V6 in the downloads with the trinity plexi mk2 preamp.normal channel is finished with parallel input 120K plate with 3.3uf/820R on the cathodes and cascade switch into the TMB channel.
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Re: A couple of my combos I’ve built:

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Doxie man wrote:
Sat 08/28/21 9:52 pm
geoff 1965 wrote:
Sat 08/28/21 9:48 pm
No offence taken! I appreciate your response,so is the F&T bias cap 33uf in yours?
Yep 👍. I never go above a 47uf. 99% of the time it’s a 25-33 in there
Personally I use 2200uF and HIGHLY prefer it to anything lower. We all have our opinions. ;) I think anything less than 1000uF sounds flubby in the low end.

Thanks,
Josh

PS. Please stop quoting yourself. There's a button to edit your posts if you have something to add, but cluttering the threads with self quotes is a little...cluttery.
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Doxie man
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Re: A couple of my combos I’ve built:

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JMPGuitars wrote:
Sun 08/29/21 7:59 pm
Doxie man wrote:
Sat 08/28/21 9:52 pm
geoff 1965 wrote:
Sat 08/28/21 9:48 pm
No offence taken! I appreciate your response,so is the F&T bias cap 33uf in yours?
Yep 👍. I never go above a 47uf. 99% of the time it’s a 25-33 in there
Personally I use 2200uF and HIGHLY prefer it to anything lower. We all have our opinions. ;) I think anything less than 1000uF sounds flubby in the low end.

Thanks,
Josh

PS. Please stop quoting yourself. There's a button to edit your posts if you have something to add, but cluttering the threads with self quotes is a little...cluttery.
Sorry about the quote thing 🤦‍♂️. I’m still getting used to this format. Every forum is different and I’m not the best at computer stuff. As to the bypass cap…
All my builds are plenty firm with a 25-47uf in there….strange 🤔
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geoff 1965
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Re: A couple of my combos I’ve built:

Post by geoff 1965 »

“Different horses for different courses!”
I like to see what values are used by other builders in certain area’s and it helps when you are voicing the amp to know what effect different values have.to be honest it sounds pretty good with the 1000uf at the moment but I have’nt nailed the TMB channel yet so when I get to the capacitance of the power tubes bias I know leaning to the 2200uf will tighten it up or I might like the sound of the lower value range.
Thanks for the input guys
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Doxie man
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Re: A couple of my combos I’ve built:

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To each his own. I like a little “bounce” in my circuits and room to breath. You can make an amp stiff and firm to the point it looses its organic textures….JMO of course.
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Re: A couple of my combos I’ve built:

Post by JMPGuitars »

Doxie man wrote:
Sun 08/29/21 9:33 pm
Sorry about the quote thing 🤦‍♂️. I’m still getting used to this format. Every forum is different and I’m not the best at computer stuff. As to the bypass cap…
All my builds are plenty firm with a 25-47uf in there….strange 🤔
No worries, I understand. You're not our first new member.

You say all your builds are plenty firm. Have you tried using 1000uF or 2200uF to compare? Did you make recordings for the comparison? It is a fairly subjective matter we're discussing anyway, so while some of us may prefer it one way, it's okay if you don't. ;)
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Re: A couple of my combos I’ve built:

Post by Doxie man »

Trust me when I tell you I’m not new to building amplifiers 😂. Keeping a circuit firm has many other areas to address in the preamp rather than a quick fix on the tail end. These 18W circuits are extremely simple and easy to build IMO. I like them certainly…I enjoy the simplicity after doing high gain stuff for a long while. You really don’t get challenged with circuit design until you get past 3 gain stages. That’s when things really start to get interesting. You ever try any of the small cathode biased Friedman stuff ? Or cathode biased Soldano’s ? They’re really great sounding and they are VERY firm & punchy…..no 1000uf-2200 bias caps anywhere to be seen in those. Anyway…..no worries…it’s all good 🤘🏻
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Re: A couple of my combos I’ve built:

Post by JMPGuitars »

Doxie man wrote:
Mon 08/30/21 9:22 am
Trust me when I tell you I’m not new to building amplifiers 😂. Keeping a circuit firm has many other areas to address in the preamp rather than a quick fix on the tail end. These 18W circuits are extremely simple and easy to build IMO. I like them certainly…I enjoy the simplicity after doing high gain stuff for a long while. You really don’t get challenged with circuit design until you get past 3 gain stages. That’s when things really start to get interesting. You ever try any of the small cathode biased Friedman stuff ? Or cathode biased Soldano’s ? They’re really great sounding and they are VERY firm & punchy…..no 1000uf-2200 bias caps anywhere to be seen in those. Anyway…..no worries…it’s all good 🤘🏻
I think the most valid point there is that circuits are different, and require different things. ;)
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