Peavey Royal 8

not a problem that i have to deal with cause i overspec everything... in my (currently being built) 2-11W amp (a forum reader is going to be a very happy owner), the load resistor is a 10 ohm 50W of this type: https://www.actionwebs.com/HotDeals/I-Sales/RH501KOHM/RH501KOHM_1.jpg. that's why i recommended you have a load of at least 20W (i like to be on the safe side cause peak wattage can be fairly larger than specced), and you won't have to worry about heat dissipation at all...

you want to be 100% safe - take two 12-16 ohm 20W resistors, wire them in parallel so you get 6-8 ohm equivalent load that can take a theoretical 40W. connect that as described in my earlier posts. in the extemely unlikely case that one resistor fails, you will still be well protected with 12-16 ohms and 20W handling capabiities.

you have to understand that this is OVERKILL - you merely want to use the resistor as a safety mechanism, i want to use mine as a power dump too, so i can take a silent line out to a sound card or something without causing the amplifier to become an amplifire in the process.

 

Out of curiosity, how much are you building it for? Specs?

How much power do you route to line out? mW?

 

i'd rather discuss that via PMs or something... it is substantially more than a royal 8 though. a few times the price.

ahhhhh now we're talking. you honestly do not want to know. let's just say i've spent a LONG time on this amp. will write that up in a new post...

much less, really. you don't want to risk frying whatever the next stage.... i still need to do the calculations, but i would estimate something in the order of nW or maybe single-figure mW range. never done a line out before.

 

I asked purely out of curiosity

Why not measure an existing line out on some amplifier and see?

 

problems: i actually can't measure it (i would need a watt meter or at least an oscilloscope), also, no other amplifier of mine has a line out (they're all DIY), but a simulation of the circuit that i plan to use gives me about 8uW into a load of 1 Meg. The voltage swing with the output volume on 100% is about 6V peak to peak, which is still a bit too much - i need to get it down to about 2V.

why the interest in the line out's power? to see if it can drive headphones? not without an additional active circuit, i would say.

 

I was just wondering how the load is offset when line-out is being used, whether it requires pin point accuracy in calculation or not.

 

i would say that the following stage is most likely to be a high-impedance stage. so the important thing would be to limit the voltage swing and the current to line levels. so accuracy is not that important, really.

 

So do amp's offer a line out because it's easier to do as compared to a mic out?

 

uhhhhh... what's a mic out? no idea what you mean.

 

There is no such thing, which is why it's curious. If most mixers can handle mic level inputs, and not all handle line level, why not incorporate the equivalent of a DI box circuit in the amp and offer balanced mic level output? What are the considerations other than space?

 

ahhh, you mean an XLR balanced out...

cost!

also, keep in mind that not everyone wants to take a direct line out into the mixer. this would necessitate a bunch of other stuff - speaker simulation etc. most people just want to mic their amps (which sounds a lot better too, and an SM57 and decentish preamp is a lt cheaper than a good DI/studio-level speaker sim).

however, most mixers will accept unbalanced line-level signals from an amp's line out - not sure why you think that this is not the case. i don't think most guitarists would miss a balanced out on their amp... in fact, i can't remember seeing a single amp in any price range with an XLR out (although i'm sure there are some in existence).

 

I meant the amps with a line out.

Although looking at it now, I guess you're right, most amps that have a line out are probably aiming to let you record to your PC, which obviously has a line in and hence should not add the requirement of having to amp the signal.

I thought they didn't because the last time I played a gig the mixer added unnecessary gain to my signal ruining even my clean sound. I assumed that the sound man had put me into a balanced XLR in (probably with preamp gain of its own) because he didn't have a line in.

 

not really. i would think the line out, if any, on amps today is a leftover from when people used one amp to drive a slave amp to get more compression and gain. it can be used for pretty much any line level input, from your interface to a mixer. what the sound guy does with it is a different matter altogether.

the line out presents a couple of problems: the easiest way to take a line out would be immediately after the preamp. this would not be dissimilar to taking a line from the "effects send" to your sound card, and is the easiest because the effects send is pretty much at the right line level too, with enough attenuation to not overload the next stage (or with a volume knob that regulates it).

however, people chirp up and say "but preamp distortion sounds like shit. i want to get the power amp distorting too and send it to a 100W solid-state amp and a guitar speaker." the amp designer must then shift the line out in with about 20:1-40:1 attenuation in parallel with the speaker jack. this is where things start getting getting iffy; there will be a substantial difference in tone if there is a speaker attached or a dummy load attached. tone could get fizzy or muddy too, and a treble bypass cap will definitely be needed somewhere.

then there's that final group that says: "this is for n00bs, i want a BALANCED line out on my amp and want to capture my cranked amp sound with speaker distortion and a mic'ed sound WITHOUT using the speaker or the mic." the patient may go and integrate this and charge the customer a bomb, but i think most amp designers would simply throw up their hands in the air and direct their customers to a dedicated device for the same, for which there is no shortage on the market.

the supposed best is: https://reviews.harmony-central.com/reviews/Effects/product/Palmer/PGA-04+Speaker+Simulator/10/1
there's also a new one by koch: https://guitars.musiciansfriend.com...-Power-AttenuatorSpeaker-Simulator?sku=609600
i heard this one personally and it sounded REALLY good. had a 100W JCM800 clone going into it on full power: https://news.harmony-central.com/Product-news/SPL-Transducer.html
a lot of people like these, and they'Re also very inexpensive: https://www.tedweber.com/atten.htm

i have not experimented much with line outs, and i think a mic'ed cab sounds the best on the whole. i wil eventually tiunker with them though, because i want to experiment with reamping.

 

You learn something new every day

Funds are still a problem.

I now might have to consider:
a) Dropping the idea altogether (since I've more or less discarded the Peavey idea, I'm leaning towards the BH5H now), and waiting until the next time someone comes down from the USA, which will probably be at least a year from now.

b) Buying the Peavey

c) Hoping for a miracle on eBay

GAS is such a bitch.

 

Ah the Peavey TKO has a low Z balanced output.

 

that''s different.... it's a bass amp. most bassists do want to send a DI to the mixer micing the speaker on a bass amp is a lot more difficult to get right too.

 

Okay now everyone's jumped on the bandwagon.

Laney has come out with the
1. Cub 8 5W Class A amplifier 110 combo: 1 ECC83 into 1 6v6GT
2. Cub 10 10W Class A/B amplifier 110 combo: 2 ECC83 into 2 6v6GT

Marshall has come out with the Class 5 5W Class A amplifier 110 combo: 2 ECC83 into 1 EL84

The Laneys are available through Bajaao. 12k for the Cub 10.

Damn this dirty itch.

 

wow. that's crazy. as much as it hurts my chances of building more tube amps, i think this is a good and long overdue development on the whole.

i'm a bit puzzled as to how they get only 10W from 2x 6V6GT though. under normal plate voltages and using the 6V6's as tetrodes, i would say there should be between 14W and 20W output available. deliberate? possibly... maybe they're running them intentionally cold.

 

Strangely enough the Laney is still not on the US market. Neither is the Marshall from what I've searched on google so far. It's only been a few months though, so who knows.

Will it affect the tone if they are running them cold like you say?

The Marshall is expensive, expectedly so. 300 quid. Are they running 2 preamps into a single poweramp so that the poweramp stage can be overdriven easily?

Is the Laney worth considering?
a) I don't need to have it brought in from the USA (although that might work out cheaper if they start selling it there)
b) It as a 10" speaker, something none of the other amps do (the BH5H is only the head)
c) It's more expensive than bringing the BH5H or whatever in for sure. 13k for the Cub 10, compared to maybe 8-9k for the BH5H

 

theoretically yes, but i don't really hear it from the youtube video i saw. sounds pretty neat.

doesn't look like it at all - the absence of a second input jack, normal or bright volume controls all point to a single preamp. no reason why two preamps should imperatively overdrive a power amp. although the power amp distortion is the final and arguably important factor (esp. where dynamics are concerned) in the tube sound, i would say the bulk of the tone shaping comes from the preamp.

single preamp in both cases - in the marshall everything points to a 2203 style first and second gain stage *possibly* with a dual pot gain control taken from the cornford harlequin. the second ECC83 is the cathode follower driving the standard marshall BMT tone stack. unless, of course, they've radically reworked the design.

with the laney - two-gain-stage preamp into phase inverter.

as far as hassles are concerned it certainly is. no idea what it sounds like though. you could always upgrade the 10" speaker to a better one later. you're extremely lucky if you know someone who agrees to lug an amp back home for you; i'd be too afraid to ask anyone i know, and am quite sure they wouldn't agree to it either.

since the B5H5 is only the head, what was your budget for the cab? that and the speaker would set you back some.