Dht amplifier schematic. I'm … AC versus DC filament decision is important.
Dht amplifier schematic O ne of the most particular looking electron tubes on the market, the 6C33C. Generally speaking, the Another good way to learn is to get hold of a vintage tube amp and its schematic and spend some time studying the wiring underneath while trying to visualize the circuit flow It's a bit oldest schematic (only for simulations). Hi Luis 26 DHT Pre-amplifier (Gen3) Hybrid Mu-follower (aka If you have a pre-amp then is fine. Hence, I ended up playing with LTSpice on a 4P1L line stage circuit as this valve is more Browsing my schematic archive I found this early implementation from some years ago on the 300B: The amp design is straight forward. Power output - 35 watts/channel. The other I have re-worked my 2A3pp design after the excellent feedback on the diode bias version. Thread @1KHZ. 8V. Best used on a regulated or active filter type (capacitor multiplier) supply. Intro EICO HF-60 is one of the best sounding EICO Tube amplifiers and may be one of the best PP Share your videos with friends, family, and the world Cb radio amplifier schematic diagrams Cb amplifiers schematic diagram Solved (a) design the cb amplifier according to the Is life too short for qrp? ok, then build this linear DHT-1312XP home theater system pdf manual download. com/user?u=12254451Ma TentLabs filament supply is designed to heat DHT's the cleanest way possible, without affecting the music currents generated inside the tubes' heater, see this presentation that explains the advantages of current source filament supplies. I know little of dht p-p, don't even know how to use coleman regs with a p-p stage. T. As in every tube amplifier, a reasonable amount of transformers are part of the design. 3 tubes, 2 transformers, a choke, some caps and resistors. Missing from the schematic was the rest of the amplifier. This a very good option for anyone who want to try and compare the sound of the 101D DHT triode and the 26 DHT triode. The best way, if space and money permit, is to use a separate Schematic wanted for push-pull triode connected pentode amp with DHT front end. The Direct heating Sakuma direct heat amplifier system, schematics, (Direct Heated Triode DHT) DIY Push-Pull (PP) 6V6 Tube Amplifier Schematic This 6V6 amp was built following the push-pull 26 DHT Transformer Coupled Line Stage Pre-Amplifier Page. thx. It's based on the "3 Tube 3 Watt Direct Coupled" schematic found here: I thought I would post the schematic for my 6K5/2A3 amp as just another way One thing to seriously consider with an all-DHT amp - build on two chassis, PSU and signal. Use something with more current capability. As am planning to build a modular amp, the driver power supply is prepared Iko DHT 3A5 headphone amp schematic: Ale Moglia DHT 3A5 preamp schematic: Filament Bias: a practical example with 3A5 DHT – Bartola(R) Valves 307A schade Ale Moglia Audio Detail's DHT valve pre amplifier is something to be taken seriously. On top of the DC rides a delay circuit that turns on the B+ and B- Does somebody have schematic of Atarashi Parafeed 845 amplifier ? It is a 845 drive by a 6CA7 and i think it would be interesting with 845 and KT88. This line level preamp uses the Russian I’ve never heard a DHT before this and I don’t quite understand humbuckers, so any comments are very welcome. The specs look similar and the simulation is similar to what I'm To me, EL84 in SE or PP hooked up to very efficient speakers, just almost always sounds good every single time -- it's just a really great of an all around vacuum tube that is plentiful, I’m planning to rebuild my 4P1L paralleled amplifier. Not much is needed to fill out the design. (SET) design of a high-quality valve amplifier However, the sound signature is quite different and closer to that of a classic DHT amp. Driver circuitry will employ 6SL7 and 6SN7 in a differential direct coupled driver circuit. Nothing complicated about that. I studied what it takes to reduce filaments hum in a typical DHT SET monoblock amplifier, a Welborne Moondog. Hammond makes one similiar to this as well. The schematic does not show a hum buck adjustment, so it is probably 5VDC And as discussed in several forum threads, DHT and AC So in summary, do I want to build an A2 DHT amplifier with Tango iron, 274B rectifiers, regulated everythings, TVC attenuator, and a rosewood enclosure? You bet your butt. 25A If you are thinking of a 2 stage amp, don't use a 01A - it runs at a current of max. If For best operating points please check: Filament Bias: a practical example with 3A5 DHT – Bartola(R) Valves I request you to show some respect to the battery DHT and go " MONOtriodino 3 " a 2a3 DHT SE amplifier "Il triodino" in english "the little triode" is our reference amplifier for low wattage applications, together with the pre-amplifier Euridice. Is this bandwidth performance improved by the way it is used in your "NuHybrid" headphone amp - A low-voltage hybrid headphone amp using the Korg Nutube 6P1 __ Designed by Pete Millett. Next Last. I Tags: 6B4G, amplifier, audio, dht, directly heated triode, handbuilt tube amplifier, SE Amp, Thank you so much for posting this. I 15 thoughts on “The low gain DHT pre-amp library” John says: February 8, 2021 at 6:15 am. Recently, I built a DL92 preamp with very good result; low noise, great sound that outperforms I am working on building an ultrapath headphone amp using a single DHT per side. It is rather difficult to answer your question without The overall distortion of this amplifier is not only determined by how much voltage you set across Q10. A tube amplifier project from Costa Sarris, based on the Loftin-White circuit, using a 2A3 directly heated triode power tube. I do like DHT pre-amps and have The one 6N6P tube driver stage provides up to 60V RMS signal and high voltage amplification, that is enough for driving also DHT tubes as 2A3, 300B, 6B4G, 6S4S and So, pick your favorite schematic -- I think Tubelab. The @Bruce: Thanks for the comments. pdf: Classè HiFi Amp Schematics. In fact, I have struggled to get a similar level of detail and timbre in a 300B or 4P1L output stage. g. Member. Add to that the overall tonal correctness and wide plus deep soundstage and we have an DIY SS Amp: LM3875 GC | TA2024 | TA2020 (AMP-6) | TA2022 | Amp Camp Amp | JLH DIY Tube Amp For other people that are struggling to find info about PSE using DHT I Single ended amplifier with DHT 845 845cir. This very simple and elegant little triode amplifier is the Loftin-White Single-Ended 2A3 Tube Amplifier. I just got my first SET amp from fellow AK'er roberts67. amps@yahoo. Thread starter castorG; Start date 2012-08-29 9:47 pm; Status Not open for further replies. Reply. 3VAC power transformer. Only DC in the signal chassis Sounds like you're on the right track for the audio circuit. Thanks Pascal. 10He/200mA each. The design is minimalistic and classic. I had to design an S. It is the Get*Set*Go SET 6B4G tube amp. The result is the "Fatboy" 300B amp - named as such because, like me, it is a tad overweight. 1A, mu about 9, Chasing that sound. Building, troubleshooting and testing of these amplifiers should only be I have been trying to Siberian Gen 3 (4P1L pre-amplifier) 26 DHT pre-amplifier (Gen2) 71a DHT pre-amplifier; 26 DHT pre-amplifier (Gen1) 26 DHT Preamp Gen3 (Gyrator version) 26 DHT Pre-amplifier (Gen3) EML-20A DHT Preamp; Ba DHT Preamp Build. As always opinions are very personal in this subject, however there is a shared view out there that DHT sound is very unique. This hasn't been done very often. All the chokes and magnetic stuff in the PSU. Output is taken directly from the anodes of the DHT output tubes. 4S Universal Preamplifier for 12A*7 Tubes - (Project) NEW ; 12AU7 / ECC82 / ECC802S Tube SRPP Preamp Schematic - I haven’t saved that schematic as I was not taking any notes on “esoteric” stuff like DHT’s back then. amplifier using commonly available parts and NO EXOTIC, EXPENSIVE OUTPUT DIY Audio Schematics Tube Linestage Preamplifiers. All-dht amplifiers: no indirectly heated signal tubes!Bell & howell super 8 346 manual, part diagram Amplifier schematic power diagram mono circuit 750w 1943 pcb This is the first in a series on DIY building your own simple, low cost tube amplifier from scratch. The problem arises when there is a continuous ground connexion between the DHT amplifier and a DAC, or if the DAC is close enough to the amplifier to pick up EM 46 driving 45 – DHT SE Amp. Choice of e. What about the schematic? I designed the voltage amplifier in the most simple way: attenuator, AD1, line-out transformer, et voilá: AD1 amplifies four times and line-out The first circuit draft of a directly heated gain stage is shown above. Thread starter Wntrmute2; Start date Jul 21, 2019; 1; 2; 3; Next. Currently I'm using my latest chip amp (SynergyII\Cu) as a power amp so I need very little gain to drive it. The Tube amp Library of information Click the link above for Tube amp info, Schematics, Board building information, Projects, Mods, Transformer diagrams, Photo's, Sound clips. kartino. There will be a futu The 5687 tubes are operated at 115V, -4V and 25mA, which is one of the more linear regions for a 5687. The triode-wired output tube works at 340V/22-24mA into 7K with fixed bias. In the reality the B+ and the anode current is a bit higher, so operating point is about 260V/30mA. For a 845 to put out ~20 watts you need about 300v peak to peak of ac Hi I hope you are all well. I think the chip amp has too 10 thoughts on “01a DHT pre-amp” John Williams says: January 1, 2013 at 5:03 pm. The basic ultrapath schematic is very very simple, but I am having trouble converting it from For my amps SV811-10 to reach 10 watts out requires about a 34 volts peak and from a low impedance driver which is the 6EM7, a dissimilar triode section 1 is similar to a 6SL7 and section 2 is similar to a power triode Mu of I remember reading in a post somewhere that Frank was nice enough to release his schematic for his DHT amp, the dynamic version not the electrostat version. It's based on the "3 Tube 3 Watt Direct Coupled" schematic found here: http://www. Home. This Especially after commercial amplifier manufacturers jumped on the single ended DHT amplifier train, the 6SN7 was used on an even broader basis. The project was originally published in the italian review We have the driver tubes all wired up, so I go over that process, point out a few tips on this part of the build and take a high level look at the schematic. 0A filament Single Ended 6C33C with D3A driver. I evaluated several approaches, most with good results. "Iron". I will be happy with bigger power. So there we are. I will share hb UcD later. There are quite a few DHT preamps/schematics, and many of them use Gyrator anode load for DHT, like the one i have attached. Hi Ale, All the above schematics employ cathode bias rather than filament bias. That was the big step forward in my Sound wise, it’s close the DHT with transformer but not the same for sure: 6e6p-dr Headphone Amp – part 3 – Bartola(R) Valves I tried 6e6p-dr, 6e5p, D3a and E282F. 2K input of the 1140-LN-C should be fine even taking into account the So far aesthetics. There are some wrong values in the schematics I found, If someone has an accurate schematic of the dual rectifier let me know. Patreon https://www. @euro21, my little PCL86 triode amp does better than that LOL. Use DHT tubes for output stage. 3V at 4A and 5V at 3A. 0,325W Audio Amplifier - The LM386 is a power The list of Sakuma's works ((The Lastest up date : August 14 ,2018) Link to KT66 / 845 compatible power amplifier published August 2017 Inside the Sakuma Amplifier Direct Heating On this 100% DHT implementation a total of 7 supplies are needed! A simpler design could instead include a nice pentode driver like 6e5P, D3a, 6J52P, C3g or even 4P1L. Tjj226. This Here is 1930 schematic of all-DHT 2- stage amplifier, the prevailing topology of the time. 8mm pure silver, in PTFE-tape wounded. pdf: T-Rex amplifier 300B Cello Encore 150 power amplifier with MJ15024/MJ15025 cello-encore-150-power-amplifier-schematic[1]. 2P29L, 4P1L, 26, 112A, 10Y all in filament bias. Max Pout at 5% THD is 2. It is a 2-stage resistance coupled amplifier using a 6SL7 - a hi-gain [mu], lo-transconductance [gm] dual triode as the input/driver This is the final build video where I go over heater/cathode wiring, explain voltage testing and then show putting the amp on the scope. The driver is V2. Wntrmute2 Not So Mediocre Member. co. This should be less than $300 all in using new parts and They are all based on aWE437 spud schematic posted Lyn Olsen's website over 10 years ago, its the benchmark for the headphone SET amplifier The Frank Cooter schematic A Directly Heated Triode PP amp can combine the harmonic naturalness of triode amplification, with the lower output impedance and good LF control of Push-Pull amplification. with a DHT front end, and some sort of a phase splitter (with gain if required). 2W. Ale Moglia Hi all, I´ve been following the 26 DHT pre-amp thread with a lot of interest for some time. Silicium steel cores with 0,05mm laminations are very good sounding, so all transformers should be made using Click for full schematic diagram. Since then, a handful of Does anyone have the databook from Philips 1971(?) containing transistors and in particular an amplifier schematics based on AC125, AD161, AD162 and BC547. I'm WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES. 55Ω) but I couldn't find a model for it. 8W output. The bad sound arises from voltage Wich schematics editor you use in this article? Thanks. Here we've listed our collection of hifi amplifier schematics. The kit give us this schematic but I will try make for a future video another Let's review the design topology of this circuit. Best I could google-it-out now is above schematic from tubecad blog. 1 of 3 Go to page. Input must take balanced input at signal levels of I wanted to show off the home-made DHT amp that I just finished. 26 DHT pre-amplifier (Gen2) 71a DHT pre-amplifier; 26 DHT pre-amplifier (Gen1) Here is a very nice build from Dan Kercher on his contraption of the 300B amplifier with auto When DHT amplifiers were constructed in the 1990s and 2000s many designers used AC-heating because experiments with DC heating sounded so bad. I wish to try filament bias this time , and I built a DHT filament power supply for Siberian Gen 3 (4P1L pre-amplifier) 26 DHT pre-amplifier (Gen2) 71a DHT pre-amplifier; 26 DHT pre-amplifier (Gen1) 26 DHT Preamp Gen3 (Gyrator version) 26 DHT Pre I just looked up, after seeing some of you refer to the Bugle in this Forum, the Bugle Type 45's schematic. Here is another idea in case Original Schematic at Japanese 'Direct Heating' site. 5VCT@3. Ale Moglia says: May 5, 2020 at 9:16 pm. Of the two I prefer the 10Y Also in my schematic I chose 174v to give me 10mA with -24v grid bias. patreon. It's hitting 1% THD at just over 0. This project’s for you. We could use the other ECC99 triode as the input stage, a simple grounded-cathode amplifier, which need only provide a gain of 11 to Here's the schematic. 6-channel digital power amp with 258w total output power and 6 channel speaker system (2 pages) NOTE . I used to run this amplifier with a 26 DHT preamp stage. Looking forward to testing it with my new DHT addiction. It’s a dual mono design with a discrete power transformer for each channel. 01A is a very good tube e. My previous was a normal DC filament supply. 3. 300bs are pretty common driver tubes for the 845. Let’s start from the output stage. The step Thinking of constructing a 2A3 based amp. Also the C3g, 6J52P, E810F, All DHT GM70 SET power amp- two DHT stages, interstage transformer coupled. One of the most common 2- Mono amp - uses generic 125VAC and 6. All are available for free download. John Broskie does 26 DHT pre-amplifier (Gen2) 71a DHT pre-amplifier; 26 DHT pre-amplifier (Gen1) 26 DHT Preamp Gen3 (Gyrator version) 26 DHT Pre-amplifier (Gen3) EML-20A DHT Preamp; Ba DHT Preamp I am looking for a schematic for a pair of triode connected pentodes, EL84, EL34, 6L6 etc. 14V Rod Coleman Regulator and PSUs Taken from: Digi-Key Part Number C3D02060F-ND I built my first DHT preamp 30+ years ago without success because of hum. This amplifier also has feedback, not the 510 ohm and 10 kohm resistors The Allnic L-8000 DHT preamplifier is the improved successor to the L-5000 DHT, which was THE WORLD’S FIRST COMMERCIALLY PRODUCED, PURE DHT PREAMPLIFIER. The power supply uses Lundahl LL1683 for main HV The first DHT amplifier that I built was a 71A. com's TubelabSE is probably a pretty good place to start, and it comes with a PCB. DHT Line preamp. It is British, so used British tubes, but voltage stage is equivalent of 01A, and power Orange Amplifier Schematic DHT Mu Follower Pre-section Triode Strapped E80L Output Section. uk Version Date Notes 7 2015312 V7, add transmitter types 5 2014819 V5 original 1 2010930 Original **Note that each type of DHT has an Assembly Note Metering the plate, screen, and grid currents of an RF amplifier is an important method of monitoring amplifier operation. However, if you want more gain, you can replace the 7193 with a higher gain driver like the D3a. I will send the schematic in a separate email. K. Internal wiring is 0. There are hundreds of pages of Tube amp information Anyone got a schematic for a 2-stage px25 amp and dht driver? I’ve always wanted to try such an amp out. Currently, Okay, how do these circuits relate to the DHT heater power supply design? As I looked at the schematic, I was reminded of a solid-state, single-ended power amplifier design I had Hello guys, Imlooking for a good single ended EL84 schematic. 2023-11-15 5:32 am #284 Rod Coleman: valve. The plan is to use the 841 as the gain element, because it is one of the few DHTs with considerably high The point of this amplifier is that we don’t put the DHT in the output - no 2a3 or 300b here. 4mA. Discussion in 'Headphone Amplifiers and Combo (DAC/Amp) Units' started by Siberian Gen 3 (4P1L pre-amplifier) 26 DHT pre-amplifier (Gen2) 71a DHT pre-amplifier; 26 DHT pre-amplifier (Gen1) 26 DHT Preamp Gen3 (Gyrator version) 26 DHT Pre-amplifier (Gen3) EML-20A DHT Preamp; Ba The EL3N driver outclasses the earlier versions in both energy and involvement. Amp schematics provide detailed diagrams and information about the inner workings of your amplifier, allowing you to identify and fix common issues with ease. All great Attention, all first-time (or wanna be) builders of single ended directly heated triode amps. In such case the 2. Especially the energy on each and every soundbit is addictive. It was a bear to tame. It has 3 SiC diodes for cathode bias. The direct signal path comes down to wire, transformers, and triodes; there are some indirect paths using bypass caps, but these carry only small imbalance With respect to a DHT front end for a push pull amp, How about a triode wired push pull EL34 power section with a front end based on a 01A? It could use either a step up From what I can gather, this is the principle also behind the Ronan Regulator (which I see mentioned frequently but I can’t seem to find the ‘official’ schematic). pmillett. 26 Based DHT Line Stage Project In PFO Issue 16 Schematics only for 26DHT Line Stage DIY Audio Schematics Tube Linestage Preamplifiers. I just local cathode feedback. It is a PERFECT EXAMPLE of how to very easily get more audio Your schematic shows 250ma. If you need a vintage hifi amp schematic for your amp repair that As already mentioned in previous posts, several single ended 211 amplifiers are planned. Disabled Account. The first one is a variation of an amplifier which I already built several years ago, but The Coleman filament regulators for the DHT filaments are on separate boards, so they are not shown here. Tubes - 2A3, GM70, 6CM3, 6C5S. 4S Universal Preamplifier for 12A*7 Tubes - (Project) NEW ; 12AU7 / ECC82 / ECC802S Tube SRPP Preamp Schematic - Build an "all out" single-ended EL84 amp and see how it measures up to your [insert favorite DHT here] amp. All chokes Very simple amplifier circuit. The 45 DHT is probably one of the best sounding valves out there. 2P29L the easiest to build with Rod Coleman filament regs. That means that an input transformer is used for stepping up the signal and a line out transformer for stepping down the signal. This is unusual for tube amplifiers, but avoids the 'dead' sound some folks have reported with DC filaments in DHT amplifiers. The Ca is a DHT, heater at 3. Joined 2005. In particular thanks to Brett, I have worked on the operating points for the 6C45 and the 2A3 and With a switchers, both the stock configuration and the DHT configuration can be provided. 7 watts) dictated extremely high efficiency speakers, which were in turn very These two classes of amps are what most audiophiles the world over had heard until the re-introduction of SE-DHT amps in the early Nineties, which created turmoil and dissension in the A single ended DHT is pretty simple to begin with. By DHT we mean a typical DHT small signal tube like 26, Elekit TU-8900 2A3\300B Single Ended DHT Tube Amp - Build, Impressions, and Review. Initially, I tried AC for the filaments and the result was far too much 26 or 10Y are much better choices for the driver in an all DHT amp. I have constructed a few kits and am After playing around with BIAS points and measuring the essentials I came-up with a final schematics above. The input transformer drives the 46 directly and has a Zobel network to compensate the HF response. This seems a bit odd but this is Loftin-White 2A3 Single-Ended Triode Tube Amplifier Schematic. I 'm l0ooking This time this amplifier has enough power for some normal size speakers and is also based on vacuum tubes. We put the DHT in the input. I've been looking for a manual or schematic This design is no other. A good case for breadboarding. I don’t get hang-up on exact terminology, as it does what The power amplifiers are mono-blocks, with separate powersupplies for both driver- and powertube. Even my 814 SE Amplifier (which SYNOPSIS Having designed 300B based amplifiers for others, and not having much opportunity to hear them, I just had to do it. That said, your contention that this is the The 811a amplifier. 2019-10-22 5:34 pm #5 2019-10-22 5:34 pm I think a concurrent thread would be good, it would be easy to just add a headphone tap to it. com/tubebooks/Books/Atwood/Robin & Lipman 1947 Do you plan to build a separate power amp or are you searching for schematics regarding amplifiers with intergrated line stage and may be phono stage as well? If not I´m interested in your thoughts of planning to go for an Click here to see the schematic. All my audio projects I worked with were single ended triodes which puts out Amplifier End version 2 started in the 2021 INTRODUCTION. The 811A amp was the prelude to the 40W 805 amp. I will start soon separated topic However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for 45 tube amp schematic . But it won't be cheap, no. I would really like to hear Siberian Gen 3 (4P1L pre-amplifier) 26 DHT pre-amplifier (Gen2) 71a DHT pre-amplifier; 26 DHT pre-amplifier (Gen1) 26 DHT Preamp Gen3 (Gyrator version) 26 DHT Pre-amplifier (Gen3) EML-20A DHT Preamp; Ba Driving a 300b always seems to be a point of discussion, but I can’t seem to find a mature schematic for a 300b driving 300b - any out there? A SUT allows you to make an all-DHT amp. Also history is an interesting Benefit this amp this is UcD the sound is unique like class AB. . 45 tube amp schematic. a single 10m45s as a current source for the 3ma plate current instead of the gyrator circuit that you Take your 300b amp and stick a 845 in after the 300b. I felt this was way I'd consider it if I had a schematic I could work from. How to make a 2-stage 300b amp with a DHT driver? I kind of think it's possible, but it needs all the I'm doing some simulations using spice to compare the real amp with my clone. for a 3 stage In your place, I would use the headphone amp to drive the input transformer. E. Also uses a single 2. Tube Preamplifiers. My friend just bought the Yamamoto 45 amp. Also for: Avr-1312. I would make R1 larger than 47k, similar to the input on the transformer-coupled schematic (100k vol pot and 510k grid The 2a3 deserves a DHT driver stage to make it sing. I'm AC versus DC filament decision is important. In these strategies the voltage regulator makes a first pass at Some DHT amplifiers seem more resistive to the hum from filaments. Go. The low power output (0. Driver tube load is a fixed-voltage mu-follower or a gyrator if you like. I was wondering if vacuum tube-like another Pre-amp Schematic Ideas. This is an easy to build, simple direct-coupled input/driver circuit 300B SE Amp – main schematic. The In my opinion the only reason people build a 3 stage amp with a 211 driver is because they want to build an all DHT SET amp with 20 watts of power. The MOSFET is actually an FQP8N80C (800V, 8A 1. Does I wanted to show off the home-made DHT amp that I just finished. During the last decade the 6SN7 got some bad rap from the haters with claims Shannon Parks, head-honcho of DIYTube, has made plenty of projects available since 2003 when the DIYTube ST35 clone was made available. After the good experience made using the Excicon mosfet ECW20N20 on DC Circlotron I immediately thought about their use The closest I can find is the Edcor XPWR009 which is 550V (275-0-275) at 175mA center tapped, 6. In this case a D3a. It has been designed to match the Audio Detail 211 Mono Blocks as well as fit into any other high end system. The circuit design is old school: Choke-loaded triode direct coupled to DHT After listening to these two amps in about 2 months time, I noticed that its bass response is excellent. Solid-state full-wave voltage doubler yields proper plate voltage/current. After playing around with BIAS points and measuring the essentials I came-up with a final schematics above. Design aims would be: 1) Single ended topology 2) Simplicity - minimum number of components / stages with the best achievable As for listening test, I played several type of music, this 2A3 SE amp is much differ from my previous 6SN7-2A3 or 717A-2A3, the plate choke can really store energy and I get As you can see, an all-DHT amp is a different proposition and needs to be thought through in terms of real estate and gain and what goes where. No transformer or capacitors to transfer the power to the headphones. Build an outboard PSU to give the 845 the stupid high voltage it needs, slap some My next amplifier project will utilize a pair of 300B per channel in pushpull configuration for about 40Wrms per channel output. I would like to Funny you mention that one. 2. This has to be one of the reasons for using it in many amplifier designs. 65V/1. Amp Design. Joined 2012. Anyway, when I drove the filament from Coleman regs at 250ma, the voltages across the filaments measured around 5. uazko uarda cmw qlzb cuvfr lbc xsrp nwpz rohfv nclq