Tried the HT5RH at practice

DanR

ecc83 said:

"Atma: low power modes (1, 5 and 18W so louder for a gig, too), small, light, 3 channels (no reverb but not a total deal-breaker). No standby switch so it pops at power on and off. "

The HT-20 of course is sans S/BY switch as well Tim but you just need to yank the guitar lead out of the front jack and the OP valves will quietly shut down. (a feature not found on the HT5 but that does of course have S/By)

Dave.

Doesn't turning your volume down on your guitar stop the popping.

Thats what I've always done on amps without standby.

ecc83

DanR said:

ecc83 said:

"Atma: low power modes (1, 5 and 18W so louder for a gig, too), small, light, 3 channels (no reverb but not a total deal-breaker). No standby switch so it pops at power on and off. "

The HT-20 of course is sans S/BY switch as well Tim but you just need to yank the guitar lead out of the front jack and the OP valves will quietly shut down. (a feature not found on the HT5 but that does of course have S/By)

Dave.

Doesn't turning your volume down on your guitar stop the popping.

Thats what I've always done on amps without standby.

I think Timmy means if you just bang the power switch off? Most amps pop a bit and those with choke filters often "chirrup".

Dave.

thomasross20

By the way..... here's a question. 
Could I have two HT5's and run one into each speaker for 10W? 
If so, how do I control the channel change for both amps at the same time? I like that idea!

thomasross20

ecc83 said:

"Atma: low power modes (1, 5 and 18W so louder for a gig, too), small, light, 3 channels (no reverb but not a total deal-breaker). No standby switch so it pops at power on and off. "

The HT-20 of course is sans S/BY switch as well Tim but you just need to yank the guitar lead out of the front jack and the OP valves will quietly shut down. (a feature not found on the HT5 but that does of course have S/By)

Dave.

Oh! 
You're not being sarcastic are you, because I can't detect sarcasm....?
It's actually best to take the lead out of that amp then power off? 

ecc83

thomasross20 said:

By the way..... here's a question. 
Could I have two HT5's and run one into each speaker for 10W? 
If so, how do I control the channel change for both amps at the same time? I like that idea!

Never tried it but you could use a Y lead to feed one footswitch to two amps, cannot see any harm could be caused. If it did go loopy all you would need is a double pole foot switch in a tin with two jacks. Beer into water to make.

Sarcasm? No, I rarely do that especially when talking  "technical" matters. How you turn on/turn off ANY Blackstar amp is up to you! Yes, some will bang/chirp if you bang mains off (Artisans) so S/B or pull the front jack on the HT-20 + and the Series Ones. But apart from unwelcome noises they won't care a shit.

Mind YOU! it would be wise with 60/100 watters to consider the speakers!

Dave.

thomasross20

@ecc83 why aren't the bias details available in the manuals, e.g. for the HT5? How is a tech supposed to re-bias such an amp? By the way the HT20 book says the power-amp is cathod-biased (you say part cathode biased?) but not what the pre-amp is. Basically... how is a tech meant to service them? 

ICBM

thomasross20 said:

@ecc83 why aren't the bias details available in the manuals, e.g. for the HT5? How is a tech supposed to re-bias such an amp? By the way the HT20 book says the power-amp is cathod-biased (you say part cathode biased?) but not what the pre-amp is. Basically... how is a tech meant to service them? 

All preamp valves are cathode-biased so you never need to worry about those. There are a very small number of phase inverters which are fixed-bias, but even those are non-adjustable so it doesn't matter either.

Any competent tech should be able to work out the correct bias setting for any power valve, in fact - all you need is the valve datasheet, the circuit voltages and in some cases an oscilloscope. (It's sometimes not possible to satisfy all the conditions at once, in which case you need to make an educated/visual/audible compromise, usually with the valves running a bit too hot - which shortens their life but doesn't generally kill them immediately.)

The HT-5 may be one of the few tricky ones because it uses a valve type most techs won't be familiar with, but the data is still available if you want it.

The HT-20 is indeed part-fixed, part-cathode biased, but you can still work out what's going on.

thomasross20

OK, no worries then - I'll leave you to it whenever it needs a service (probably never knowing Blackstar)

ecc83

thomasross20 said:

@ecc83 why aren't the bias details available in the manuals, e.g. for the HT5? How is a tech supposed to re-bias such an amp? By the way the HT20 book says the power-amp is cathod-biased (you say part cathode biased?) but not what the pre-amp is. Basically... how is a tech meant to service them? 

This is not an "official" reply but. Blackstar take the (some say extreme) view that Joe P should not poke about inside their amplifiers. They also don't want to make things easy for the likes of Behringer (not that it stopped them!) .

Then we no longer have a network of qualified technicians* around the country as was the case 40 or so years ago in the Radio&TV trade (the punter would look for the "RTRA" trade logo) and if my experience of THAT trade when I left it some 20yrs ago is anything to go by, there are a lot of unqualified amp "techs"  around now! Personally I am in favour of a more open dissemination of service data but a ***ked up repair can do incalculable damage to a companies reputation.

As ICBM says, biasing an amp is not rocket science if you can understand a data sheet. The amplifiers as a whole are not unduly sensitive to bias settings. You WOULD need the service sheet to check the power control in a Series One but then the company has an excellent in house service dept (ask for Phil) and their charges are reasonable.

*.."You" can have cheap OR an army of great techs. Not both.

Dave.

thomasross20

I'd like to try the HT20 and HT5 side-by-side to see which is louder but I don't think there's that much in it. 
I have to say, I think the HT5 is a real gem. Small and light and feels more fun to play than the HT20 - I might change my mind next week and then the week after ;D So, so good...